Make a robust sending system

app/shared/build.gradle.kts

@@ -83,6 +83,7 @@ kotlin {
         }
 
         androidMain.dependencies {
+            implementation(libs.androidx.exifinterface)
             implementation(libs.ktor.client.okhttp)
             implementation(libs.firebase.messaging)
             implementation(libs.androidx.activity.compose)
@@ -117,6 +118,10 @@ compose.resources {
     generateResClass = auto
 }
 
+tasks.matching { it.name == "compileAndroidMain" || it.name == "compileKotlinIosArm64" }.configureEach {
+    dependsOn("generateResourceAccessorsForCommonMain")
+}
+
 tasks.register("generateResourceAccessors") {
     dependsOn(
         *(

app/shared/src/androidMain/AndroidManifest.xml

@@ -1,14 +1,20 @@
 <?xml version="1.0" encoding="utf-8"?>
-<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools">
 
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE_CAMERA" />
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE_MICROPHONE" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_DATA_SYNC" />
 
     <application>
         <service
             android:name="ru.fromchat.calls.CallForegroundService"
             android:exported="false"
             android:foregroundServiceType="camera|microphone" />
+        <service
+            android:name="androidx.work.impl.foreground.SystemForegroundService"
+            android:foregroundServiceType="dataSync"
+            tools:node="merge" />
     </application>
 </manifest>

app/shared/src/androidMain/kotlin/ru/fromchat/api/ApiClient.android.kt

@@ -3,5 +3,14 @@ package ru.fromchat.api
 import io.ktor.client.HttpClient
 import io.ktor.client.HttpClientConfig
 import io.ktor.client.engine.okhttp.OkHttp
+import io.ktor.client.plugins.HttpTimeout
 
-actual fun createPlatformHttpClient(block: HttpClientConfig<*>.() -> Unit) = HttpClient(OkHttp, block)
+actual fun createPlatformHttpClient(block: HttpClientConfig<*>.() -> Unit) =
+    HttpClient(OkHttp) {
+        install(HttpTimeout) {
+            requestTimeoutMillis = 30_000
+            connectTimeoutMillis = 5_000
+            socketTimeoutMillis = 30_000
+        }
+        block()
+    }

app/shared/src/androidMain/kotlin/ru/fromchat/api/AttachmentUploadQueue.android.kt

@@ -1,294 +1,28 @@
 package ru.fromchat.api
 
-import android.content.Context
-import android.net.Uri
-import java.io.File
-import org.json.JSONObject
-import androidx.work.BackoffPolicy
-import androidx.work.Constraints
-import androidx.work.CoroutineWorker
-import androidx.work.Data
-import androidx.work.ExistingWorkPolicy
-import androidx.work.NetworkType
-import androidx.work.OneTimeWorkRequestBuilder
-import androidx.work.WorkManager
-import androidx.work.WorkerParameters
-import com.pr0gramm3r101.utils.UtilsLibrary
-import com.pr0gramm3r101.utils.crypto.Base64
-import com.pr0gramm3r101.utils.settings.settings
-import java.util.concurrent.TimeUnit
-import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.MainScope
 import kotlinx.coroutines.flow.SharedFlow
-import kotlinx.coroutines.runBlocking
-import ru.fromchat.crypto.transport.TransportCiphertext
-import ru.fromchat.crypto.transport.TransportCrypto
-
-private const val INLINE_UPLOAD_THRESHOLD_BYTES = 512 * 1024
-private const val DEFAULT_CHUNK_SIZE = 262_144
-
-private fun dmBlobCacheFile(context: Context, jobId: String): File =
-    File(context.cacheDir, "dm_resumable_$jobId.blob")
-
-private fun dmTransportCipherPrefsKey(jobId: String): String = "dm_upload_transport_cipher_$jobId"
-
-private object AttachmentUploadEvents {
-    val flow = MutableSharedFlow<AttachmentUploadProgress>(extraBufferCapacity = 64)
-}
+import kotlinx.coroutines.launch
+import ru.fromchat.api.outbox.OutgoingMessageCoordinator
+import ru.fromchat.api.outbox.scheduleOutboxProcessing
+import ru.fromchat.core.cache.CacheContext
 
 actual object AttachmentUploadQueue {
-    actual val progressFlow: SharedFlow<AttachmentUploadProgress> = AttachmentUploadEvents.flow
+    actual val progressFlow: SharedFlow<AttachmentUploadProgress> = AttachmentUploadNotifier.progressFlow
 
     actual fun enqueue(job: AttachmentUploadJob) {
-        AttachmentUploadEvents.flow.tryEmit(
-            AttachmentUploadProgress.Pending(
-                jobId = job.jobId,
-                filename = job.filename
-            )
-        )
-
-        val request = OneTimeWorkRequestBuilder<DmAttachmentUploadWorker>()
-            .setInputData(
-                Data.Builder()
-                    .putString(DmAttachmentUploadWorker.KEY_JOB_ID, job.jobId)
-                    .putString(DmAttachmentUploadWorker.KEY_FILE_URI, job.fileUri)
-                    .putString(DmAttachmentUploadWorker.KEY_FILENAME, job.filename)
-                    .putInt(DmAttachmentUploadWorker.KEY_RECIPIENT_ID, job.recipientId)
-                    .putString(DmAttachmentUploadWorker.KEY_PLAINTEXT, job.plaintext)
-                    .build()
-            )
-            .setConstraints(
-                Constraints.Builder()
-                    .setRequiredNetworkType(NetworkType.CONNECTED)
-                    .build()
-            )
-            .setBackoffCriteria(
-                BackoffPolicy.EXPONENTIAL,
-                10,
-                TimeUnit.SECONDS
-            )
-            .build()
-
-        WorkManager.getInstance(UtilsLibrary.context).enqueueUniqueWork(
-            uniqueWorkName(job.jobId),
-            ExistingWorkPolicy.REPLACE,
-            request
-        )
+        scheduleOutboxProcessing(CacheContext.activeInstanceId.value.trim())
     }
 
     actual fun cancel(jobId: String) {
-        val ctx = UtilsLibrary.context
-        dmBlobCacheFile(ctx, jobId).delete()
-        runBlocking {
-            settings.putString(dmTransportCipherPrefsKey(jobId), "")
+        val instanceId = CacheContext.activeInstanceId.value.trim()
+        if (instanceId.isEmpty()) return
+        MainScope().launch {
+            val row = ru.fromchat.api.db.MessageDatabaseProvider.database.messageDatabaseQueries
+                .selectOutboxItem(instanceId, jobId.trim())
+                .executeAsOneOrNull()
+            val conversationId = row?.conversationId ?: return@launch
+            OutgoingMessageCoordinator.cancelOutboundMessage(jobId, conversationId)
         }
-        WorkManager.getInstance(ctx).cancelUniqueWork(uniqueWorkName(jobId))
-    }
-
-    private fun uniqueWorkName(jobId: String): String = "dm-attachment-upload-$jobId"
-}
-
-class DmAttachmentUploadWorker(
-    appContext: Context,
-    params: WorkerParameters
-) : CoroutineWorker(appContext, params) {
-    companion object {
-        const val KEY_JOB_ID = "job_id"
-        const val KEY_FILE_URI = "file_uri"
-        const val KEY_FILENAME = "filename"
-        const val KEY_RECIPIENT_ID = "recipient_id"
-        const val KEY_PLAINTEXT = "plaintext"
-    }
-
-    override suspend fun doWork(): Result {
-        val jobId = inputData.getString(KEY_JOB_ID)
-            ?: return Result.failure()
-        val fileUri = inputData.getString(KEY_FILE_URI)
-            ?: return Result.failure()
-        val filename = inputData.getString(KEY_FILENAME)
-            ?: "file"
-        val recipientId = inputData.getInt(KEY_RECIPIENT_ID, -1)
-        val plaintext = inputData.getString(KEY_PLAINTEXT)?.trim().orEmpty()
-
-        if (recipientId <= 0) return Result.failure()
-        if (plaintext.isBlank()) return Result.failure()
-
-        return runCatching {
-            emitProgress(jobId, 0)
-
-            val prepared = loadPreparedTransportAndBlob(applicationContext, jobId)
-            val encryptedBlob: ByteArray
-            val msgCipher: TransportCiphertext
-
-            if (prepared != null) {
-                encryptedBlob = prepared.first
-                msgCipher = prepared.second
-            } else {
-                val staleUploadId = settings.getString(uploadIdKey(jobId), "").ifBlank { null }
-                if (staleUploadId != null) {
-                    runCatching { ApiClient.abortDmUpload(staleUploadId) }
-                    settings.putString(uploadIdKey(jobId), "")
-                }
-
-                val transportKey = ApiClient.getTransportPublicKey()
-                val (freshCipher, ephemeralSecret) = TransportCrypto.encryptWithTransportKeyWithEphemeralSecret(
-                    plaintext = plaintext,
-                    transportPublicKeyB64 = transportKey.publicKeyB64
-                )
-                try {
-                    val bytes = applicationContext.contentResolver.openInputStream(Uri.parse(fileUri))?.use { it.readBytes() }
-                        ?: error("Failed to read file from URI")
-                    val blob = TransportCrypto.encryptFileForTransport(
-                        fileBytes = bytes,
-                        transportPublicKeyB64 = transportKey.publicKeyB64,
-                        ephemeralSecretKey = ephemeralSecret
-                    )
-                    encryptedBlob = blob
-                    msgCipher = freshCipher
-                    savePreparedTransportAndBlob(applicationContext, jobId, encryptedBlob, msgCipher)
-                } finally {
-                    ephemeralSecret.fill(0)
-                }
-            }
-
-            if (encryptedBlob.size <= INLINE_UPLOAD_THRESHOLD_BYTES) {
-                sendInline(jobId, recipientId, plaintext, filename, encryptedBlob, msgCipher)
-            } else {
-                sendResumable(jobId, recipientId, plaintext, filename, encryptedBlob, msgCipher)
-            }
-
-            clearPreparedTransportAndBlob(applicationContext, jobId)
-            clearResumableState(jobId)
-            AttachmentUploadEvents.flow.tryEmit(AttachmentUploadProgress.Success(jobId))
-            Result.success()
-        }.getOrElse { error ->
-            AttachmentUploadEvents.flow.tryEmit(
-                AttachmentUploadProgress.Failed(
-                    jobId = jobId,
-                    error = error.message ?: "Upload failed"
-                )
-            )
-            if (runAttemptCount >= 5) Result.failure() else Result.retry()
-        }
-    }
-
-    private suspend fun sendInline(
-        jobId: String,
-        recipientId: Int,
-        plaintext: String,
-        filename: String,
-        encryptedBlob: ByteArray,
-        msgCipher: TransportCiphertext
-    ) {
-        val file = SendDmFile(
-            encryptedFileDataB64 = Base64.encode(encryptedBlob),
-            filename = filename,
-            fileSize = encryptedBlob.size.toLong()
-        )
-        ApiClient.sendDm(
-            recipientId = recipientId,
-            plaintext = plaintext,
-            clientMessageId = jobId,
-            transportFiles = listOf(file),
-            preparedTransport = msgCipher
-        )
-    }
-
-    private suspend fun sendResumable(
-        jobId: String,
-        recipientId: Int,
-        plaintext: String,
-        filename: String,
-        encryptedBlob: ByteArray,
-        msgCipher: TransportCiphertext
-    ) {
-        val uploadId = settings.getString(uploadIdKey(jobId), "").ifBlank {
-            val init = ApiClient.initDmUpload(
-                filename = filename,
-                totalSize = encryptedBlob.size.toLong(),
-                recipientId = recipientId,
-                chunkSize = DEFAULT_CHUNK_SIZE
-            )
-            settings.putString(uploadIdKey(jobId), init.uploadId)
-            init.uploadId
-        }
-
-        var offset = ApiClient.getDmUploadStatus(uploadId).offset.toInt()
-        while (offset < encryptedBlob.size) {
-            val nextOffset = minOf(offset + DEFAULT_CHUNK_SIZE, encryptedBlob.size)
-            val chunk = encryptedBlob.copyOfRange(offset, nextOffset)
-            ApiClient.uploadDmChunk(
-                uploadId = uploadId,
-                offset = offset.toLong(),
-                dataB64 = Base64.encode(chunk)
-            )
-            offset = nextOffset
-            emitProgress(jobId, ((offset.toDouble() / encryptedBlob.size.toDouble()) * 100.0).toInt())
-        }
-
-        val completed = ApiClient.completeDmUpload(uploadId)
-        ApiClient.sendDm(
-            recipientId = recipientId,
-            plaintext = plaintext,
-            clientMessageId = jobId,
-            uploadedFileIds = listOf(completed.fileId),
-            preparedTransport = msgCipher
-        )
-    }
-
-    private fun emitProgress(jobId: String, value: Int) {
-        AttachmentUploadEvents.flow.tryEmit(
-            AttachmentUploadProgress.InProgress(
-                jobId = jobId,
-                percent = value.coerceIn(0, 100)
-            )
-        )
-    }
-
-    private suspend fun clearResumableState(jobId: String) {
-        settings.putString(uploadIdKey(jobId), "")
-    }
-
-    private fun uploadIdKey(jobId: String): String = "dm_upload_id_$jobId"
-
-    private suspend fun savePreparedTransportAndBlob(
-        context: Context,
-        jobId: String,
-        blob: ByteArray,
-        cipher: TransportCiphertext
-    ) {
-        val f = dmBlobCacheFile(context, jobId)
-        f.outputStream().use { it.write(blob) }
-        val json = JSONObject().apply {
-            put("clientPublicKeyB64", cipher.clientPublicKeyB64)
-            put("nonceB64", cipher.nonceB64)
-            put("ciphertextB64", cipher.ciphertextB64)
-        }
-        settings.putString(dmTransportCipherPrefsKey(jobId), json.toString())
-    }
-
-    private suspend fun loadPreparedTransportAndBlob(
-        context: Context,
-        jobId: String
-    ): Pair<ByteArray, TransportCiphertext>? {
-        val f = dmBlobCacheFile(context, jobId)
-        val raw = settings.getString(dmTransportCipherPrefsKey(jobId), "").ifBlank { return null }
-        if (!f.isFile || f.length() == 0L) return null
-        return try {
-            val o = JSONObject(raw)
-            val cipher = TransportCiphertext(
-                clientPublicKeyB64 = o.getString("clientPublicKeyB64"),
-                nonceB64 = o.getString("nonceB64"),
-                ciphertextB64 = o.getString("ciphertextB64")
-            )
-            f.readBytes() to cipher
-        } catch (_: Exception) {
-            null
-        }
-    }
-
-    private suspend fun clearPreparedTransportAndBlob(context: Context, jobId: String) {
-        dmBlobCacheFile(context, jobId).delete()
-        settings.putString(dmTransportCipherPrefsKey(jobId), "")
     }
 }
-

app/shared/src/androidMain/kotlin/ru/fromchat/api/db/MessageDatabaseDriver.android.kt

@@ -3,13 +3,41 @@ package ru.fromchat.api.db
 import app.cash.sqldelight.db.SqlDriver
 import app.cash.sqldelight.driver.android.AndroidSqliteDriver
 import com.pr0gramm3r101.utils.UtilsLibrary
+import androidx.sqlite.db.SupportSQLiteDatabase
+import java.io.File
 import ru.fromchat.db.MessageDatabase
 
 actual fun provideMessageDatabaseDriver(): SqlDriver {
+    val context = UtilsLibrary.context
+    val fromchatDir = File(context.cacheDir, "fromchat").apply { mkdirs() }
+    val dbFile = File(fromchatDir, "message_database.db")
+    removeLegacyDatabaseFiles(context.getDatabasePath("message_database.db"))
     return AndroidSqliteDriver(
         schema = MessageDatabase.Schema,
-        context = UtilsLibrary.context,
-        name = "message_database.db"
+        context = context,
+        name = dbFile.absolutePath,
+        callback = DiffOnlyDatabaseCallback(),
     )
 }
 
+/** Drops the pre-cache-dir DB; message cache lives under cache only. */
+private fun removeLegacyDatabaseFiles(legacyDb: File) {
+    if (!legacyDb.exists()) return
+    runCatching { legacyDb.delete() }
+    runCatching { File("${legacyDb.path}-journal").delete() }
+    runCatching { File("${legacyDb.path}-wal").delete() }
+    runCatching { File("${legacyDb.path}-shm").delete() }
+}
+
+/**
+ * SQLDelight [user_version] is not used for migrations; [ensureMessageDatabaseSchema] diffs structure.
+ */
+private class DiffOnlyDatabaseCallback : AndroidSqliteDriver.Callback(MessageDatabase.Schema) {
+    override fun onCreate(db: SupportSQLiteDatabase) {
+        // Schema is created by structural diff on first open.
+    }
+
+    override fun onUpgrade(db: SupportSQLiteDatabase, oldVersion: Int, newVersion: Int) {
+        // No version-based migration.
+    }
+}

app/shared/src/androidMain/kotlin/ru/fromchat/api/db/MessageDatabaseLock.android.kt

@@ -0,0 +1,5 @@
+package ru.fromchat.api.db
+
+private val lock = Any()
+
+internal actual fun <T> withMessageDatabaseLock(block: () -> T): T = synchronized(lock, block)

app/shared/src/androidMain/kotlin/ru/fromchat/api/outbox/MediaUploadForegroundHelper.kt

@@ -0,0 +1,72 @@
+package ru.fromchat.api.outbox
+
+import android.app.Notification
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.content.Context
+import android.content.pm.ServiceInfo
+import android.os.Build
+import androidx.core.app.NotificationCompat
+import androidx.work.ForegroundInfo
+import com.pr0gramm3r101.utils.UtilsLibrary
+import org.jetbrains.compose.resources.getString
+import ru.fromchat.Res
+import ru.fromchat.notif_media_upload_channel_name
+import ru.fromchat.notif_media_upload_progress
+import ru.fromchat.notif_media_upload_text
+import ru.fromchat.notif_media_upload_title
+
+private const val CHANNEL_ID = "fromchat_media_upload"
+private const val NOTIFICATION_ID = 0xFC10
+
+object MediaUploadForegroundHelper {
+    suspend fun foregroundInfo(
+        context: Context = UtilsLibrary.context,
+        percent: Int? = null,
+        filename: String? = null,
+    ): ForegroundInfo {
+        val channelName = getString(Res.string.notif_media_upload_channel_name)
+        val title = getString(Res.string.notif_media_upload_title)
+        val defaultText = getString(Res.string.notif_media_upload_text)
+        ensureChannel(context, channelName)
+        val contentText = when {
+            percent != null && !filename.isNullOrBlank() ->
+                getString(Res.string.notif_media_upload_progress, percent.coerceIn(0, 100), filename)
+            percent != null -> "$percent%"
+            else -> defaultText
+        }
+        val builder = NotificationCompat.Builder(context, CHANNEL_ID)
+            .setContentTitle(title)
+            .setContentText(contentText)
+            .setSmallIcon(android.R.drawable.stat_sys_upload)
+            .setOngoing(true)
+            .setOnlyAlertOnce(true)
+            .setPriority(NotificationCompat.PRIORITY_LOW)
+            .setCategory(Notification.CATEGORY_PROGRESS)
+        when (val p = percent?.coerceIn(0, 100)) {
+            null -> builder.setProgress(100, 0, true)
+            else -> builder.setProgress(100, p, false)
+        }
+        val notification = builder.build()
+        return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
+            ForegroundInfo(
+                NOTIFICATION_ID,
+                notification,
+                ServiceInfo.FOREGROUND_SERVICE_TYPE_DATA_SYNC,
+            )
+        } else {
+            ForegroundInfo(NOTIFICATION_ID, notification)
+        }
+    }
+
+    private fun ensureChannel(context: Context, channelName: String) {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) return
+        val manager = context.getSystemService(NotificationManager::class.java) ?: return
+        val channel = NotificationChannel(
+            CHANNEL_ID,
+            channelName,
+            NotificationManager.IMPORTANCE_LOW,
+        )
+        manager.createNotificationChannel(channel)
+    }
+}

app/shared/src/androidMain/kotlin/ru/fromchat/api/outbox/OutboxProcessor.android.kt

@@ -0,0 +1,39 @@
+package ru.fromchat.api.outbox
+
+import androidx.work.Constraints
+import androidx.work.Data
+import androidx.work.ExistingWorkPolicy
+import androidx.work.NetworkType
+import androidx.work.OneTimeWorkRequestBuilder
+import androidx.work.OutOfQuotaPolicy
+import androidx.work.WorkManager
+import com.pr0gramm3r101.utils.UtilsLibrary
+
+actual fun scheduleOutboxProcessing(instanceId: String) {
+    val id = instanceId.trim()
+    if (id.isEmpty()) return
+    val request = OneTimeWorkRequestBuilder<OutboxSendWorker>()
+        .setInputData(
+            Data.Builder()
+                .putString(OutboxSendWorker.KEY_INSTANCE_ID, id)
+                .build(),
+        )
+        .setConstraints(
+            Constraints.Builder()
+                .setRequiredNetworkType(NetworkType.CONNECTED)
+                .build(),
+        )
+        .setExpedited(OutOfQuotaPolicy.RUN_AS_NON_EXPEDITED_WORK_REQUEST)
+        .build()
+    WorkManager.getInstance(UtilsLibrary.context).enqueueUniqueWork(
+        "outbox-send-$id",
+        ExistingWorkPolicy.APPEND_OR_REPLACE,
+        request,
+    )
+}
+
+actual fun cancelOutboxProcessing(instanceId: String) {
+    val id = instanceId.trim()
+    if (id.isEmpty()) return
+    WorkManager.getInstance(UtilsLibrary.context).cancelUniqueWork("outbox-send-$id")
+}

app/shared/src/androidMain/kotlin/ru/fromchat/api/outbox/OutboxSendWorker.kt

@@ -0,0 +1,63 @@
+package ru.fromchat.api.outbox
+
+import android.content.Context
+import androidx.work.CoroutineWorker
+import androidx.work.WorkerParameters
+import kotlinx.coroutines.coroutineScope
+import kotlinx.coroutines.launch
+import ru.fromchat.api.AttachmentUploadNotifier
+import ru.fromchat.api.AttachmentUploadProgress
+import ru.fromchat.core.cache.CacheContext
+
+class OutboxSendWorker(
+    context: Context,
+    params: WorkerParameters,
+) : CoroutineWorker(context, params) {
+
+    override suspend fun doWork(): Result = coroutineScope {
+        val instanceId = inputData.getString(KEY_INSTANCE_ID)?.trim().orEmpty()
+            .ifEmpty { CacheContext.activeInstanceId.value.trim() }
+        if (instanceId.isEmpty()) return@coroutineScope Result.success()
+        val hasMedia = DmAttachmentOutboxHandler.hasPendingAttachmentWork(instanceId)
+        val progressJob = if (hasMedia) {
+            launch {
+                AttachmentUploadNotifier.progressFlow.collect { progress ->
+                    when (progress) {
+                        is AttachmentUploadProgress.InProgress -> {
+                            setForeground(
+                                MediaUploadForegroundHelper.foregroundInfo(
+                                    percent = progress.percent,
+                                    filename = progress.filename,
+                                ),
+                            )
+                        }
+                        is AttachmentUploadProgress.Pending -> {
+                            setForeground(
+                                MediaUploadForegroundHelper.foregroundInfo(
+                                    percent = 0,
+                                    filename = progress.filename,
+                                ),
+                            )
+                        }
+                        else -> Unit
+                    }
+                }
+            }
+        } else {
+            null
+        }
+        if (hasMedia) {
+            setForeground(MediaUploadForegroundHelper.foregroundInfo(percent = 0))
+        }
+        val allOk = try {
+            OutgoingMessageCoordinator.drainOutboxForInstance(instanceId)
+        } finally {
+            progressJob?.cancel()
+        }
+        Result.success()
+    }
+
+    companion object {
+        const val KEY_INSTANCE_ID = "instance_id"
+    }
+}

app/shared/src/androidMain/kotlin/ru/fromchat/core/cache/FromChatCacheDirs.android.kt

@@ -0,0 +1,12 @@
+package ru.fromchat.core.cache
+
+import com.pr0gramm3r101.utils.UtilsLibrary
+import java.io.File
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+
+actual suspend fun wipeFromChatCacheDirectory() {
+    withContext(Dispatchers.IO) {
+        File(UtilsLibrary.context.cacheDir, "fromchat").deleteRecursively()
+    }
+}

app/shared/src/androidMain/kotlin/ru/fromchat/core/cache/FromChatCacheGeneration.android.kt

@@ -0,0 +1,30 @@
+package ru.fromchat.core.cache
+
+import com.pr0gramm3r101.utils.UtilsLibrary
+import java.io.File
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import ru.fromchat.api.db.MessageDatabaseProvider
+import ru.fromchat.core.cache.wipeFromChatCacheDirectory
+
+private const val GENERATION_FILE = ".generation"
+
+actual suspend fun ensureFromChatCacheGeneration() {
+    withContext(Dispatchers.IO) {
+        val root = File(UtilsLibrary.context.cacheDir, "fromchat")
+        val marker = File(root, GENERATION_FILE)
+        if (marker.isFile) return@withContext
+        MessageDatabaseProvider.closeAndReset()
+        wipeFromChatCacheDirectory()
+        marker.parentFile?.mkdirs()
+        marker.writeText("1\n")
+    }
+}
+
+actual suspend fun writeFromChatCacheGeneration() {
+    withContext(Dispatchers.IO) {
+        val root = File(UtilsLibrary.context.cacheDir, "fromchat")
+        root.mkdirs()
+        File(root, GENERATION_FILE).writeText("1\n")
+    }
+}

app/shared/src/androidMain/kotlin/ru/fromchat/core/cache/ResumableUploadStorage.android.kt

@@ -0,0 +1,108 @@
+package ru.fromchat.core.cache
+
+import android.net.Uri
+import com.pr0gramm3r101.utils.UtilsLibrary
+import java.io.File
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+
+private fun uploadDir(instanceId: String): File {
+    val safe = instanceId.replace(Regex("[^a-zA-Z0-9._-]"), "_")
+    return File(UtilsLibrary.context.cacheDir, "fromchat/instances/$safe/uploads").apply { mkdirs() }
+}
+
+private fun blobFile(instanceId: String, clientMessageId: String): File {
+    val safeId = clientMessageId.replace(Regex("[^a-zA-Z0-9._-]"), "_")
+    return File(uploadDir(instanceId), "$safeId.enc")
+}
+
+private fun cipherFile(instanceId: String, clientMessageId: String): File {
+    val safeId = clientMessageId.replace(Regex("[^a-zA-Z0-9._-]"), "_")
+    return File(uploadDir(instanceId), "$safeId.cipher.json")
+}
+
+private fun sourceFile(instanceId: String, clientMessageId: String): File {
+    val safeId = clientMessageId.replace(Regex("[^a-zA-Z0-9._-]"), "_")
+    return File(uploadDir(instanceId), "$safeId.source")
+}
+
+actual suspend fun stageOutboundFileForUpload(
+    instanceId: String,
+    clientMessageId: String,
+    sourceUri: String,
+): StagedOutboundFile = withContext(Dispatchers.IO) {
+    val dest = sourceFile(instanceId, clientMessageId)
+    val destUri = Uri.fromFile(dest).toString()
+    if (sourceUri != destUri && sourceUri != dest.absolutePath) {
+        if (!dest.isFile || dest.length() == 0L) {
+            val input = when {
+                sourceUri.startsWith("content://") || sourceUri.startsWith("file://") ->
+                    UtilsLibrary.context.contentResolver.openInputStream(Uri.parse(sourceUri))
+                else -> File(sourceUri).inputStream()
+            } ?: throw OutboundFileUnavailableException("Failed to read file from URI")
+            input.use { inputStream ->
+                dest.outputStream().use { output -> inputStream.copyTo(output) }
+            }
+        }
+    }
+    StagedOutboundFile(uri = destUri, sizeBytes = dest.length().coerceAtLeast(0L))
+}
+
+actual suspend fun readOutboundFileBytes(fileUri: String): ByteArray =
+    withContext(Dispatchers.IO) {
+        when {
+            fileUri.startsWith("content://") ->
+                UtilsLibrary.context.contentResolver.openInputStream(Uri.parse(fileUri))?.use { it.readBytes() }
+                    ?: throw OutboundFileUnavailableException("Failed to read file from URI")
+            fileUri.startsWith("file://") -> {
+                val path = Uri.parse(fileUri).path ?: throw OutboundFileUnavailableException("Invalid file URI")
+                val file = File(path)
+                if (!file.isFile) throw OutboundFileUnavailableException("File no longer exists")
+                file.readBytes()
+            }
+            else -> {
+                val file = File(fileUri)
+                if (!file.isFile) throw OutboundFileUnavailableException("File no longer exists")
+                file.readBytes()
+            }
+        }
+    }
+
+actual suspend fun saveEncryptedUploadBlob(instanceId: String, clientMessageId: String, bytes: ByteArray) {
+    withContext(Dispatchers.IO) {
+        blobFile(instanceId, clientMessageId).outputStream().use { it.write(bytes) }
+    }
+}
+
+actual suspend fun loadEncryptedUploadBlob(instanceId: String, clientMessageId: String): ByteArray? =
+    withContext(Dispatchers.IO) {
+        val f = blobFile(instanceId, clientMessageId)
+        if (!f.isFile || f.length() == 0L) null else f.readBytes()
+    }
+
+actual suspend fun saveUploadTransportCipherJson(instanceId: String, clientMessageId: String, json: String) {
+    withContext(Dispatchers.IO) {
+        cipherFile(instanceId, clientMessageId).writeText(json)
+    }
+}
+
+actual suspend fun loadUploadTransportCipherJson(instanceId: String, clientMessageId: String): String? =
+    withContext(Dispatchers.IO) {
+        val f = cipherFile(instanceId, clientMessageId)
+        if (!f.isFile) null else f.readText().takeIf { it.isNotBlank() }
+    }
+
+actual suspend fun clearUploadArtifacts(instanceId: String, clientMessageId: String) {
+    withContext(Dispatchers.IO) {
+        blobFile(instanceId, clientMessageId).delete()
+        cipherFile(instanceId, clientMessageId).delete()
+        sourceFile(instanceId, clientMessageId).delete()
+    }
+}
+
+actual suspend fun clearUploadSecretsOnly(instanceId: String, clientMessageId: String) {
+    withContext(Dispatchers.IO) {
+        blobFile(instanceId, clientMessageId).delete()
+        cipherFile(instanceId, clientMessageId).delete()
+    }
+}

app/shared/src/androidMain/kotlin/ru/fromchat/crypto/dm/DmCrypto.android.kt

@@ -34,17 +34,27 @@ actual object DmCrypto {
     actual suspend fun decryptEnvelope(
         ivB64: String,
         ciphertextB64: String,
-        mek: ByteArray
+        mek: ByteArray,
     ): ByteArray = withContext(Dispatchers.Default) {
-        require(mek.size == AES_KEY_SIZE) { "MEK must be 32 bytes" }
-
         val iv = Base64.decode(ivB64)
         val ciphertext = Base64.decode(ciphertextB64)
+        decryptAesGcmRaw(iv, ciphertext, mek)
+    }
 
+    actual suspend fun decryptAesGcm(
+        ivB64: String,
+        ciphertext: ByteArray,
+        mek: ByteArray,
+    ): ByteArray = withContext(Dispatchers.Default) {
+        val iv = Base64.decode(ivB64)
+        decryptAesGcmRaw(iv, ciphertext, mek)
+    }
+
+    private suspend fun decryptAesGcmRaw(iv: ByteArray, ciphertext: ByteArray, mek: ByteArray): ByteArray {
+        require(mek.size == AES_KEY_SIZE) { "MEK must be 32 bytes" }
         require(iv.size == GCM_IV_SIZE) { "IV must be 12 bytes" }
         require(ciphertext.size >= GCM_TAG_SIZE) { "Ciphertext too short" }
-
-        try {
+        return try {
             BackupCryptoPlatform.aesGcmDecrypt(mek, iv, ciphertext)
         } catch (e: GeneralSecurityException) {
             throw DmCiphertextCorruptedException(cause = e)

app/shared/src/androidMain/kotlin/ru/fromchat/ui/chat/AttachmentPickers.android.kt

@@ -3,6 +3,7 @@ package ru.fromchat.ui.chat
 import android.graphics.BitmapFactory
 import android.net.Uri
 import android.provider.OpenableColumns
+import androidx.exifinterface.media.ExifInterface
 import androidx.activity.compose.rememberLauncherForActivityResult
 import androidx.activity.result.PickVisualMediaRequest
 import androidx.activity.result.contract.ActivityResultContracts
@@ -22,12 +23,100 @@ actual fun getFilenameFromUri(uri: String): String {
 
 actual suspend fun getImageAspectRatio(uri: String): Float? {
     val context = com.pr0gramm3r101.utils.UtilsLibrary.context
-    context.contentResolver.openInputStream(Uri.parse(uri))?.use { stream ->
+    val parsed = Uri.parse(uri)
+    val orientation = when {
+        parsed.scheme == "content" || parsed.scheme == "file" -> {
+            runCatching {
+                context.contentResolver.openInputStream(parsed)?.use { stream ->
+                    ExifInterface(stream).getAttributeInt(
+                        ExifInterface.TAG_ORIENTATION,
+                        ExifInterface.ORIENTATION_NORMAL,
+                    )
+                }
+            }.getOrNull() ?: ExifInterface.ORIENTATION_NORMAL
+        }
+        else -> {
+            val path = parsed.path
+            if (path != null) {
+                runCatching {
+                    ExifInterface(path).getAttributeInt(
+                        ExifInterface.TAG_ORIENTATION,
+                        ExifInterface.ORIENTATION_NORMAL,
+                    )
+                }.getOrNull() ?: ExifInterface.ORIENTATION_NORMAL
+            } else {
+                ExifInterface.ORIENTATION_NORMAL
+            }
+        }
+    }
+    context.contentResolver.openInputStream(parsed)?.use { stream ->
         val options = BitmapFactory.Options().apply { inJustDecodeBounds = true }
         BitmapFactory.decodeStream(stream, null, options)
-        val w = options.outWidth
-        val h = options.outHeight
-        if (w > 0 && h > 0) return w.toFloat() / h
+        var w = options.outWidth
+        var h = options.outHeight
+        if (w <= 0 || h <= 0) return null
+        when (orientation) {
+            ExifInterface.ORIENTATION_ROTATE_90,
+            ExifInterface.ORIENTATION_ROTATE_270,
+            ExifInterface.ORIENTATION_TRANSPOSE,
+            ExifInterface.ORIENTATION_TRANSVERSE,
+            -> {
+                val swap = w
+                w = h
+                h = swap
+            }
+        }
+        return w.toFloat() / h.toFloat()
+    }
+    return null
+}
+
+actual suspend fun getImageDimensions(uri: String): Pair<Int, Int>? {
+    val context = com.pr0gramm3r101.utils.UtilsLibrary.context
+    val parsed = Uri.parse(uri)
+    val orientation = when {
+        parsed.scheme == "content" || parsed.scheme == "file" -> {
+            runCatching {
+                context.contentResolver.openInputStream(parsed)?.use { stream ->
+                    ExifInterface(stream).getAttributeInt(
+                        ExifInterface.TAG_ORIENTATION,
+                        ExifInterface.ORIENTATION_NORMAL,
+                    )
+                }
+            }.getOrNull() ?: ExifInterface.ORIENTATION_NORMAL
+        }
+        else -> {
+            val path = parsed.path
+            if (path != null) {
+                runCatching {
+                    ExifInterface(path).getAttributeInt(
+                        ExifInterface.TAG_ORIENTATION,
+                        ExifInterface.ORIENTATION_NORMAL,
+                    )
+                }.getOrNull() ?: ExifInterface.ORIENTATION_NORMAL
+            } else {
+                ExifInterface.ORIENTATION_NORMAL
+            }
+        }
+    }
+    context.contentResolver.openInputStream(parsed)?.use { stream ->
+        val options = BitmapFactory.Options().apply { inJustDecodeBounds = true }
+        BitmapFactory.decodeStream(stream, null, options)
+        var w = options.outWidth
+        var h = options.outHeight
+        if (w <= 0 || h <= 0) return null
+        when (orientation) {
+            ExifInterface.ORIENTATION_ROTATE_90,
+            ExifInterface.ORIENTATION_ROTATE_270,
+            ExifInterface.ORIENTATION_TRANSPOSE,
+            ExifInterface.ORIENTATION_TRANSVERSE,
+            -> {
+                val swap = w
+                w = h
+                h = swap
+            }
+        }
+        return w to h
     }
     return null
 }

app/shared/src/androidMain/kotlin/ru/fromchat/ui/chat/LocalDecodedImageCache.android.kt

@@ -0,0 +1,144 @@
+package ru.fromchat.ui.chat
+
+import android.graphics.Bitmap
+import android.graphics.BitmapFactory
+import android.graphics.Matrix
+import android.util.LruCache
+import androidx.compose.ui.graphics.ImageBitmap
+import androidx.compose.ui.graphics.asImageBitmap
+import androidx.exifinterface.media.ExifInterface
+
+actual object PlatformDecodedBitmapCache {
+    private val cache: LruCache<String, ImageBitmap> = object : LruCache<String, ImageBitmap>(maxCacheBytes()) {
+        override fun sizeOf(key: String, value: ImageBitmap): Int =
+            value.width * value.height * 4
+    }
+
+    actual fun get(key: String): ImageBitmap? = cache.get(key)
+
+    actual fun put(key: String, bitmap: ImageBitmap) {
+        cache.put(key, bitmap)
+    }
+
+    actual fun remove(key: String) {
+        cache.remove(key)
+    }
+
+    actual fun evictPrefix(prefix: String) {
+        val snapshot = cache.snapshot()
+        for (entryKey in snapshot.keys) {
+            if (entryKey.startsWith(prefix)) {
+                cache.remove(entryKey)
+            }
+        }
+    }
+
+    private fun maxCacheBytes(): Int =
+        (Runtime.getRuntime().maxMemory() / 8).toInt().coerceAtLeast(4 * 1024 * 1024)
+}
+
+actual fun decodeLocalImageFile(absolutePath: String, reqWidthPx: Int, reqHeightPx: Int): ImageBitmap? =
+    decodeSampledFromFile(absolutePath, reqWidthPx, reqHeightPx)?.asImageBitmap()
+
+actual fun decodeImageBytes(bytes: ByteArray, reqWidthPx: Int, reqHeightPx: Int): ImageBitmap? =
+    decodeSampledFromBytes(bytes, reqWidthPx, reqHeightPx)?.asImageBitmap()
+
+private fun decodeSampledFromFile(path: String, reqWidthPx: Int, reqHeightPx: Int): Bitmap? {
+    val orientation = readExifOrientation(path)
+    val bounds = BitmapFactory.Options().apply { inJustDecodeBounds = true }
+    BitmapFactory.decodeFile(path, bounds)
+    if (bounds.outWidth <= 0 || bounds.outHeight <= 0) return null
+    val (orientedW, orientedH) = orientedDimensions(bounds.outWidth, bounds.outHeight, orientation)
+    val sampleSize = calculateInSampleSize(orientedW, orientedH, reqWidthPx, reqHeightPx)
+    val options = BitmapFactory.Options().apply {
+        inSampleSize = sampleSize
+        inPreferredConfig = Bitmap.Config.ARGB_8888
+    }
+    val decoded = BitmapFactory.decodeFile(path, options) ?: return null
+    val oriented = applyExifOrientation(decoded, orientation)
+    return scaleBitmapToFitWithin(oriented, reqWidthPx, reqHeightPx)
+}
+
+private fun decodeSampledFromBytes(bytes: ByteArray, reqWidthPx: Int, reqHeightPx: Int): Bitmap? {
+    val bounds = BitmapFactory.Options().apply { inJustDecodeBounds = true }
+    BitmapFactory.decodeByteArray(bytes, 0, bytes.size, bounds)
+    if (bounds.outWidth <= 0 || bounds.outHeight <= 0) return null
+    val sampleSize = calculateInSampleSize(bounds.outWidth, bounds.outHeight, reqWidthPx, reqHeightPx)
+    val options = BitmapFactory.Options().apply {
+        inSampleSize = sampleSize
+        inPreferredConfig = Bitmap.Config.ARGB_8888
+    }
+    val decoded = BitmapFactory.decodeByteArray(bytes, 0, bytes.size, options) ?: return null
+    return scaleBitmapToFitWithin(decoded, reqWidthPx, reqHeightPx)
+}
+
+/** Downscale only — never upscale or crop; [ContentScale.Crop] on the tile handles fill. */
+private fun scaleBitmapToFitWithin(bitmap: Bitmap, reqWidthPx: Int, reqHeightPx: Int): Bitmap {
+    if (bitmap.width <= reqWidthPx && bitmap.height <= reqHeightPx) return bitmap
+    val scale = minOf(
+        reqWidthPx.toFloat() / bitmap.width.toFloat(),
+        reqHeightPx.toFloat() / bitmap.height.toFloat(),
+    )
+    if (scale >= 1f) return bitmap
+    val dstW = (bitmap.width * scale).toInt().coerceAtLeast(1)
+    val dstH = (bitmap.height * scale).toInt().coerceAtLeast(1)
+    return Bitmap.createScaledBitmap(bitmap, dstW, dstH, true)
+}
+
+private fun readExifOrientation(path: String): Int =
+    runCatching {
+        ExifInterface(path).getAttributeInt(
+            ExifInterface.TAG_ORIENTATION,
+            ExifInterface.ORIENTATION_NORMAL,
+        )
+    }.getOrDefault(ExifInterface.ORIENTATION_NORMAL)
+
+private fun orientedDimensions(width: Int, height: Int, orientation: Int): Pair<Int, Int> =
+    when (orientation) {
+        ExifInterface.ORIENTATION_ROTATE_90,
+        ExifInterface.ORIENTATION_ROTATE_270,
+        ExifInterface.ORIENTATION_TRANSPOSE,
+        ExifInterface.ORIENTATION_TRANSVERSE,
+        -> height to width
+        else -> width to height
+    }
+
+private fun applyExifOrientation(bitmap: Bitmap, orientation: Int): Bitmap {
+    val matrix = Matrix()
+    when (orientation) {
+        ExifInterface.ORIENTATION_ROTATE_90 -> matrix.postRotate(90f)
+        ExifInterface.ORIENTATION_ROTATE_180 -> matrix.postRotate(180f)
+        ExifInterface.ORIENTATION_ROTATE_270 -> matrix.postRotate(270f)
+        ExifInterface.ORIENTATION_FLIP_HORIZONTAL -> matrix.postScale(-1f, 1f)
+        ExifInterface.ORIENTATION_FLIP_VERTICAL -> matrix.postScale(1f, -1f)
+        ExifInterface.ORIENTATION_TRANSPOSE -> {
+            matrix.postRotate(90f)
+            matrix.postScale(-1f, 1f)
+        }
+        ExifInterface.ORIENTATION_TRANSVERSE -> {
+            matrix.postRotate(270f)
+            matrix.postScale(-1f, 1f)
+        }
+        else -> return bitmap
+    }
+    return Bitmap.createBitmap(bitmap, 0, 0, bitmap.width, bitmap.height, matrix, true)
+        ?: bitmap
+}
+
+/** Android docs: largest inSampleSize where both dimensions stay >= requested. */
+private fun calculateInSampleSize(
+    width: Int,
+    height: Int,
+    reqWidthPx: Int,
+    reqHeightPx: Int,
+): Int {
+    var inSampleSize = 1
+    if (height > reqHeightPx || width > reqWidthPx) {
+        var halfHeight = height / 2
+        var halfWidth = width / 2
+        while (halfHeight / inSampleSize >= reqHeightPx && halfWidth / inSampleSize >= reqWidthPx) {
+            inSampleSize *= 2
+        }
+    }
+    return inSampleSize.coerceAtLeast(1)
+}

app/shared/src/commonMain/composeResources/values-ru/strings.xml

@@ -64,16 +64,25 @@
     <string name="notif_call_channel_name">Активный звонок</string>
     <string name="notif_call_ongoing_title">Видеозвонок</string>
     <string name="notif_call_ongoing_text">Камера и микрофон остаются включёнными, пока вы вне приложения</string>
+    <string name="notif_media_upload_channel_name">Загрузка медиа</string>
+    <string name="notif_media_upload_title">Отправка вложения</string>
+    <string name="notif_media_upload_text">Загрузка продолжается в фоне</string>
     <string name="message_sender_you">Вы</string>
     <string name="user_fallback">Человек %1$d</string>
     <string name="message_corrupted">Это сообщение не удалось показать.</string>
     <string name="message_edited_suffix">(изменено)</string>
     <string name="message_replying_to">Ответ %1$s</string>
     <string name="message_corrupted_short">Сообщение не показывается</string>
+    <string name="attachment_image_load_failed">Не удалось загрузить</string>
+    <string name="attachment_retry">Повторить</string>
+    <string name="cd_attachment_retry">Повторить загрузку изображения</string>
     <string name="message_editing_title">Правка сообщения</string>
     <string name="action_reply">Ответить</string>
     <string name="action_edit">Изменить</string>
     <string name="action_delete">Удалить</string>
+    <string name="action_copy">Копировать</string>
+    <string name="action_cancel_send">Отменить</string>
+    <string name="notif_media_upload_progress">%1$d%% · %2$s</string>
     <string name="action_save">Сохранить</string>
     <string name="cd_close">Закрыть</string>
     <string name="cd_remove">Убрать</string>
@@ -152,6 +161,16 @@
     <string name="server_config_action_reset">Сбросить</string>
     <string name="server_config_action_reset_confirm_title">Сбросить настройки?</string>
     <string name="server_config_action_reset_confirm_body">Будут восстановлены адрес сервера и порты по умолчанию.</string>
+    <string name="server_config_unsupported_no_instance_id">Сервер не предоставляет корректный ID экземпляра. Подключение невозможно.</string>
+    <string name="server_config_snackbar_timeout">Сервер не ответил вовремя. Повторите попытку.</string>
+    <string name="server_config_checking">Проверка…</string>
+    <string name="server_config_session_logged_out_no_instance">Сессия завершена: не удалось определить ID экземпляра сервера.</string>
+
+    <string name="action_wipe_local_cache_title">Очистить локальные данные</string>
+    <string name="action_wipe_local_cache_supporting">Удаляет кэш сообщений, медиа и отложенные отправки на этом устройстве. Аккаунт на сервере не затрагивается.</string>
+    <string name="action_wipe_local_cache_confirm_title">Очистить локальные данные?</string>
+    <string name="action_wipe_local_cache_confirm_body">Будут удалены офлайн-сообщения и загрузки для всех экземпляров сервера на этом устройстве. Неотправленные сообщения из очереди будут потеряны.</string>
+    <string name="action_wipe_local_cache_done">Локальные данные очищены</string>
     <string name="save_continue">Сохранить и продолжить</string>
     <string name="change_server">Сменить сервер</string>
     <string name="change_server_d">Подключиться к альтернативному серверу FromChat и выйти из аккаунта.</string>

app/shared/src/commonMain/composeResources/values/strings.xml

@@ -75,6 +75,9 @@
     <string name="notif_call_channel_name">Ongoing call</string>
     <string name="notif_call_ongoing_title">Video call</string>
     <string name="notif_call_ongoing_text">Camera and microphone stay active while you’re away</string>
+    <string name="notif_media_upload_channel_name">Media upload</string>
+    <string name="notif_media_upload_title">Sending attachment</string>
+    <string name="notif_media_upload_text">Upload continues in the background</string>
 
     <!-- Messages -->
     <string name="message_sender_you">You</string>
@@ -83,13 +86,19 @@
     <string name="message_edited_suffix">(edited)</string>
     <string name="message_replying_to">Reply to %1$s</string>
     <string name="message_corrupted_short">Can’t show this message</string>
+    <string name="attachment_image_load_failed">Failed to load</string>
+    <string name="attachment_retry">Retry</string>
+    <string name="cd_attachment_retry">Retry loading image</string>
     <string name="message_editing_title">Edit message</string>
 
     <!-- Message actions -->
     <string name="action_reply">Reply</string>
     <string name="action_edit">Edit</string>
     <string name="action_delete">Delete</string>
+    <string name="action_copy">Copy</string>
+    <string name="action_cancel_send">Cancel</string>
     <string name="action_save">Save</string>
+    <string name="notif_media_upload_progress">%1$d%% · %2$s</string>
 
     <!-- Chat input -->
     <string name="cd_close">Close</string>
@@ -179,6 +188,17 @@
     <string name="server_config_action_reset">Reset</string>
     <string name="server_config_action_reset_confirm_title">Reset to defaults?</string>
     <string name="server_config_action_reset_confirm_body">This restores the default server and port settings.</string>
+    <string name="server_config_unsupported_no_instance_id">This server does not provide a valid instance ID. Cannot connect.</string>
+    <string name="server_config_snackbar_timeout">Server did not respond in time. Try again.</string>
+    <string name="server_config_checking">Checking…</string>
+    <string name="server_config_session_logged_out_no_instance">Session ended: server instance ID could not be resolved.</string>
+
+    <!-- Local offline data wipe (Settings → Server tools) -->
+    <string name="action_wipe_local_cache_title">Clear local data</string>
+    <string name="action_wipe_local_cache_supporting">Removes cached messages, media, and pending sends on this device. Your account on the server is not affected.</string>
+    <string name="action_wipe_local_cache_confirm_title">Clear local data?</string>
+    <string name="action_wipe_local_cache_confirm_body">All offline messages and downloads for every server instance on this device will be deleted. Unsent messages in the outbox will be lost.</string>
+    <string name="action_wipe_local_cache_done">Local data cleared</string>
     <string name="save_continue">Save and continue</string>
 
     <!-- Settings -->

app/shared/src/commonMain/kotlin/ru/fromchat/api/ApiClient.kt

@@ -18,6 +18,14 @@ import io.ktor.client.plugins.websocket.pingInterval
 import io.ktor.client.request.bearerAuth
 import io.ktor.client.request.delete
 import io.ktor.client.request.get
+import io.ktor.client.statement.bodyAsChannel
+import io.ktor.http.HttpHeaders
+import io.ktor.http.HttpStatusCode
+import io.ktor.http.contentLength
+import io.ktor.utils.io.core.isEmpty
+import io.ktor.utils.io.core.readBytes
+import io.ktor.utils.io.readRemaining
+import com.pr0gramm3r101.utils.files.PlatformFileSystem
 import io.ktor.client.request.patch
 import io.ktor.client.request.parameter
 import io.ktor.client.request.post
@@ -36,6 +44,8 @@ import kotlinx.serialization.json.Json
 import kotlinx.serialization.json.encodeToJsonElement
 import ru.fromchat.core.Settings
 import ru.fromchat.core.config.Config
+import ru.fromchat.core.instance.InstanceIdGuard
+import ru.fromchat.api.db.InstanceRegistryStore
 import ru.fromchat.ui.chat.PublicChatPanelCache
 import ru.fromchat.ui.dm.DmPanelCache
 import ru.fromchat.fcm.uploadPendingFcmTokenIfAvailable
@@ -150,6 +160,12 @@ object ApiClient {
         // - 403 => forbidden, keep session intact (used for read-only/suspension workflows).
         HttpResponseValidator {
             validateResponse { response ->
+                val instanceHeader = response.headers[InstanceIdGuard.INSTANCE_ID_HEADER]
+                runCatching {
+                    Config.serverConfig.value?.let { cfg ->
+                        InstanceIdGuard.onResponseHeader(instanceHeader, cfg)
+                    }
+                }
                 if (response.status.value == 401) {
                     token = null
                     user = null
@@ -194,6 +210,20 @@ object ApiClient {
             defaultRequest {
                 header("User-Agent", userAgent)
             }
+            HttpResponseValidator {
+                validateResponse { response ->
+                    val instanceHeader = response.headers[InstanceIdGuard.INSTANCE_ID_HEADER]
+                    runCatching {
+                        InstanceIdGuard.onResponseHeader(instanceHeader)
+                    }
+                    if (response.status.value !in (200..299) + 101) {
+                        throw ClientRequestException(
+                            response,
+                            response.status.description,
+                        )
+                    }
+                }
+            }
         }
     }
 
@@ -222,6 +252,7 @@ object ApiClient {
             val id = fetchServerInstanceId(Config.apiBaseUrl)
             if (id.isNotEmpty()) {
                 Settings.lastKnownServerInstanceId = id
+                InstanceRegistryStore.registerInstanceEncountered(id)
             }
         }
     }
@@ -546,16 +577,147 @@ object ApiClient {
      * Fetch encrypted file bytes. Path is e.g. "/uploads/files/encrypted/xxx.jpg" or "/api/uploads/files/encrypted/xxx.jpg".
      * Backend may return path with /api prefix; apiBaseUrl already includes /api, so we avoid double /api.
      */
-    suspend fun fetchEncryptedFile(path: String): ByteArray {
-        val url = when {
-            path.startsWith("http") -> path
-            path.startsWith("/api") -> {
-                val serverBase = Config.apiBaseUrl.removeSuffix("/api")
-                "$serverBase$path"
-            }
-            else -> "${Config.apiBaseUrl}$path"
+    fun encryptedFileUrl(path: String): String = when {
+        path.startsWith("http") -> path
+        path.startsWith("/api") -> {
+            val serverBase = Config.apiBaseUrl.removeSuffix("/api")
+            "$serverBase$path"
+        }
+        else -> "${Config.apiBaseUrl}$path"
+    }
+
+    suspend fun fetchEncryptedFile(path: String): ByteArray =
+        fetchEncryptedFileResumable(path, resumeKey = null, onProgress = null)
+
+    /**
+     * Downloads encrypted file bytes with optional resume ([resumeKey] partial on disk) and progress.
+     */
+    suspend fun fetchEncryptedFileResumable(
+        path: String,
+        resumeKey: String?,
+        onProgress: ((percent: Int) -> Unit)?,
+    ): ByteArray {
+        val url = encryptedFileUrl(path)
+        val partialPath = resumeKey?.let { partialEncryptedDownloadPath(it) }
+        val prefix = partialPath?.let { readPartialEncryptedBytes(it) } ?: ByteArray(0)
+        val offset = prefix.size
+
+        onProgress?.invoke(if (offset > 0) percentForBytes(offset, offset.coerceAtLeast(1)) else 1)
+
+        val response = http.get(url) {
+            if (offset > 0) {
+                header(HttpHeaders.Range, "bytes=$offset-")
+            }
+        }
+
+        return when (response.status) {
+            HttpStatusCode.PartialContent -> {
+                readDownloadBody(
+                    response = response,
+                    prefix = prefix,
+                    partialPath = partialPath,
+                    onProgress = onProgress,
+                )
+            }
+            HttpStatusCode.OK -> {
+                if (offset > 0) {
+                    partialPath?.let { PlatformFileSystem.delete(it) }
+                }
+                readDownloadBody(
+                    response = response,
+                    prefix = if (offset > 0) ByteArray(0) else prefix,
+                    partialPath = partialPath,
+                    onProgress = onProgress,
+                )
+            }
+            else -> {
+                val bytes = response.body<ByteArray>()
+                onProgress?.invoke(100)
+                partialPath?.let { PlatformFileSystem.delete(it) }
+                bytes
+            }
+        }
+    }
+
+    private suspend fun readDownloadBody(
+        response: HttpResponse,
+        prefix: ByteArray,
+        partialPath: String?,
+        onProgress: ((percent: Int) -> Unit)?,
+    ): ByteArray {
+        val channel = response.bodyAsChannel()
+        var buffer = prefix
+        var received = prefix.size
+        val totalBytes = responseTotalBytes(response, received)
+
+        while (!channel.isClosedForRead) {
+            val packet = channel.readRemaining(16 * 1024)
+            if (packet.isEmpty) break
+            val chunk = packet.readBytes()
+            if (chunk.isEmpty()) continue
+            buffer = buffer + chunk
+            received += chunk.size
+            partialPath?.let { PlatformFileSystem.writeBytes(it, buffer) }
+            onProgress?.invoke(
+                if (totalBytes != null && totalBytes > 0) {
+                    percentForBytes(received, totalBytes)
+                } else {
+                    (received / 32_768).coerceIn(1, 99)
+                },
+            )
+        }
+
+        onProgress?.invoke(100)
+        partialPath?.let { PlatformFileSystem.delete(it) }
+        return buffer
+    }
+
+    private fun responseTotalBytes(response: HttpResponse, receivedSoFar: Int): Int? {
+        val contentRange = response.headers[HttpHeaders.ContentRange]
+        if (contentRange != null) {
+            val total = contentRange.substringAfterLast('/').toLongOrNull()
+            if (total != null && total > 0L) return total.toInt()
+        }
+        val contentLength = response.contentLength()?.toInt()
+        return when {
+            response.status == HttpStatusCode.PartialContent && contentLength != null ->
+                receivedSoFar + contentLength
+            contentLength != null && contentLength > 0 -> contentLength
+            else -> null
+        }
+    }
+
+    /** Drops a partial encrypted download so the next attempt starts clean. */
+    fun clearPartialEncryptedDownload(resumeKey: String) {
+        partialEncryptedDownloadPath(resumeKey)?.let { path ->
+            runCatching { PlatformFileSystem.delete(path) }
+        }
+    }
+
+    private fun partialEncryptedDownloadPath(resumeKey: String): String? {
+        val base = PlatformFileSystem.getAppCacheDirectory()
+        if (base.isEmpty()) return null
+        val dir = "$base/encrypted_downloads"
+        PlatformFileSystem.ensureDirectory(dir)
+        val safe = resumeKey.replace(Regex("[^a-zA-Z0-9._-]"), "_")
+        return "$dir/partial_$safe.enc"
+    }
+
+    private suspend fun readPartialEncryptedBytes(path: String): ByteArray? {
+        if (!PlatformFileSystem.exists(path)) return null
+        return runCatching {
+            ru.fromchat.core.cache.readOutboundFileBytes("file://$path")
+        }.getOrNull()?.takeIf { it.isNotEmpty() }
+    }
+
+    private fun percentForBytes(received: Int, total: Int): Int {
+        if (received <= 0 || total <= 0) return 0
+        val raw = ((received.toDouble() / total.toDouble()) * 100.0).toInt()
+        return when {
+            raw <= 0 -> 1
+            raw >= 100 -> 99
+            else -> raw
         }
-        return http.get(url).body()
     }
 
     /**
@@ -812,6 +974,25 @@ object ApiClient {
         )
     }
 
+    suspend fun deleteDm(messageId: Int, recipientId: Int) {
+        if (_suspensionState.value.isSuspended) return
+        WebSocketManager.send(
+            WebSocketMessage(
+                type = "dmDelete",
+                credentials = WebSocketCredentials(
+                    scheme = "Bearer",
+                    credentials = getTokenSafely()
+                ),
+                data = json.encodeToJsonElement(
+                    WebSocketDeleteDmRequest(
+                        id = messageId,
+                        recipientId = recipientId,
+                    )
+                )
+            )
+        )
+    }
+
     suspend fun sendTyping() {
         if (_suspensionState.value.isSuspended) return
         runCatching {

app/shared/src/commonMain/kotlin/ru/fromchat/api/AttachmentDownloadNotifier.kt

@@ -0,0 +1,117 @@
+package ru.fromchat.api
+
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.SharedFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.update
+import kotlinx.coroutines.launch
+import ru.fromchat.ui.chat.AttachmentMediaLog
+import ru.fromchat.ui.chat.DecryptedImageCache
+
+sealed class AttachmentDownloadProgress {
+    data class InProgress(val storageKey: String, val percent: Int) : AttachmentDownloadProgress()
+    data class Success(
+        val storageKey: String,
+        val messageId: Int = 0,
+    ) : AttachmentDownloadProgress()
+    data class Failed(val storageKey: String, val error: String) : AttachmentDownloadProgress()
+}
+
+/**
+ * In-chat download/decrypt progress (no system notification).
+ * [progressPercentByKey] is the source of truth for UI; [progressFlow] is for one-shot side effects.
+ */
+object AttachmentDownloadNotifier {
+    private val _progressFlow = MutableSharedFlow<AttachmentDownloadProgress>(extraBufferCapacity = 64)
+    val progressFlow: SharedFlow<AttachmentDownloadProgress> = _progressFlow
+
+    private val _progressPercentByKey = MutableStateFlow<Map<String, Int>>(emptyMap())
+    val progressPercentByKey: StateFlow<Map<String, Int>> = _progressPercentByKey.asStateFlow()
+
+    private val _failedKeys = MutableStateFlow<Set<String>>(emptySet())
+    val failedKeys: StateFlow<Set<String>> = _failedKeys.asStateFlow()
+
+    private val mainScope = CoroutineScope(SupervisorJob() + Dispatchers.Main)
+
+    fun emit(
+        progress: AttachmentDownloadProgress,
+        messageLabel: String? = null,
+        messageId: Int = 0,
+        fileIndex: Int = 0,
+        clientMessageId: String? = null,
+    ) {
+        val msg = AttachmentMediaLog.messageLabel(messageLabel)
+        val primaryKey = when (progress) {
+            is AttachmentDownloadProgress.InProgress -> progress.storageKey
+            is AttachmentDownloadProgress.Success -> progress.storageKey
+            is AttachmentDownloadProgress.Failed -> progress.storageKey
+        }
+        val mirrorKeys = DecryptedImageCache.progressLookupKeys(
+            messageId = messageId,
+            fileIndex = fileIndex,
+            clientMessageId = clientMessageId,
+        ).ifEmpty { listOf(primaryKey) }
+        when (progress) {
+            is AttachmentDownloadProgress.InProgress -> {
+                if (progress.percent == 1 || progress.percent % 15 == 0 || progress.percent >= 95) {
+                    AttachmentMediaLog.download(
+                        "progress",
+                        "key" to progress.storageKey,
+                        "pct" to progress.percent,
+                        "msg" to msg,
+                        "mirror" to mirrorKeys.joinToString(","),
+                    )
+                }
+            }
+            is AttachmentDownloadProgress.Success ->
+                AttachmentMediaLog.download(
+                    "success",
+                    "key" to progress.storageKey,
+                    "msgId" to progress.messageId,
+                    "msg" to msg,
+                )
+            is AttachmentDownloadProgress.Failed ->
+                AttachmentMediaLog.download(
+                    "failed",
+                    "key" to progress.storageKey,
+                    "err" to progress.error,
+                    "msg" to msg,
+                )
+        }
+        when (progress) {
+            is AttachmentDownloadProgress.InProgress -> {
+                val pct = progress.percent.coerceIn(1, 100)
+                _progressPercentByKey.update { map ->
+                    map + mirrorKeys.associateWith { pct }
+                }
+            }
+            is AttachmentDownloadProgress.Success -> {
+                _progressPercentByKey.update { map ->
+                    map + mirrorKeys.associateWith { 100 }
+                }
+            }
+            is AttachmentDownloadProgress.Failed -> {
+                _progressPercentByKey.update { map -> map - mirrorKeys.toSet() }
+                _failedKeys.update { keys -> keys + mirrorKeys.toSet() }
+            }
+        }
+        mainScope.launch {
+            _progressFlow.emit(progress)
+        }
+    }
+
+    fun clearProgress(messageId: Int, fileIndex: Int, clientMessageId: String? = null) {
+        val keys = DecryptedImageCache.progressLookupKeys(messageId, fileIndex, clientMessageId).toSet()
+        _progressPercentByKey.update { map -> map - keys }
+        _failedKeys.update { failed -> failed - keys }
+    }
+
+    fun isFailed(messageId: Int, fileIndex: Int, clientMessageId: String? = null): Boolean =
+        DecryptedImageCache.progressLookupKeys(messageId, fileIndex, clientMessageId)
+            .any { it in _failedKeys.value }
+}

app/shared/src/commonMain/kotlin/ru/fromchat/api/AttachmentUploadNotifier.kt

@@ -0,0 +1,52 @@
+package ru.fromchat.api
+
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.flow.SharedFlow
+import kotlinx.coroutines.launch
+import ru.fromchat.ui.chat.AttachmentMediaLog
+
+/** Shared upload/download progress events (outbox worker + UI + decrypt pipeline). */
+object AttachmentUploadNotifier {
+    private val _progressFlow = MutableSharedFlow<AttachmentUploadProgress>(extraBufferCapacity = 64)
+    val progressFlow: SharedFlow<AttachmentUploadProgress> = _progressFlow
+    private val mainScope = CoroutineScope(SupervisorJob() + Dispatchers.Main)
+
+    fun emit(progress: AttachmentUploadProgress, messageLabel: String? = null) {
+        val msg = AttachmentMediaLog.messageLabel(messageLabel)
+        when (progress) {
+            is AttachmentUploadProgress.Pending ->
+                AttachmentMediaLog.upload(
+                    "pending",
+                    "job" to progress.jobId,
+                    "file" to progress.filename,
+                    "msg" to msg,
+                )
+            is AttachmentUploadProgress.InProgress -> {
+                if (progress.percent == 1 || progress.percent % 10 == 0 || progress.percent >= 95) {
+                    AttachmentMediaLog.upload(
+                        "progress",
+                        "job" to progress.jobId,
+                        "pct" to progress.percent,
+                        "file" to progress.filename,
+                        "msg" to msg,
+                    )
+                }
+            }
+            is AttachmentUploadProgress.Success ->
+                AttachmentMediaLog.upload("success", "job" to progress.jobId, "msg" to msg)
+            is AttachmentUploadProgress.Failed ->
+                AttachmentMediaLog.upload(
+                    "failed",
+                    "job" to progress.jobId,
+                    "err" to progress.error,
+                    "msg" to msg,
+                )
+        }
+        mainScope.launch {
+            _progressFlow.emit(progress)
+        }
+    }
+}

app/shared/src/commonMain/kotlin/ru/fromchat/api/AttachmentUploadQueue.kt

@@ -13,7 +13,7 @@ data class AttachmentUploadJob(
 
 sealed class AttachmentUploadProgress {
     data class Pending(val jobId: String, val filename: String) : AttachmentUploadProgress()
-    data class InProgress(val jobId: String, val percent: Int) : AttachmentUploadProgress()
+    data class InProgress(val jobId: String, val percent: Int, val filename: String? = null) : AttachmentUploadProgress()
     data class Success(val jobId: String) : AttachmentUploadProgress()
     data class Failed(val jobId: String, val error: String) : AttachmentUploadProgress()
 }

app/shared/src/commonMain/kotlin/ru/fromchat/api/ClientMessageId.kt

@@ -0,0 +1,14 @@
+package ru.fromchat.api
+
+import korlibs.crypto.SHA256
+import kotlin.random.Random
+import kotlin.time.Clock
+
+/**
+ * Opaque id for optimistic send / server ack matching.
+ * SHA-256 hex of send-time material (epoch ms + nonce); echoed to the sender only on [dmNew].
+ */
+fun generateClientMessageId(): String {
+    val material = "${Clock.System.now().toEpochMilliseconds()}:${Random.nextInt()}"
+    return SHA256.digest(material.encodeToByteArray()).hexLower
+}

app/shared/src/commonMain/kotlin/ru/fromchat/api/MessageOrdering.kt

@@ -0,0 +1,18 @@
+package ru.fromchat.api
+
+/**
+ * Chat list order: confirmed messages by time, then outgoing queued (negative id) at the bottom.
+ * Avoids optimistic rows jumping mid-thread when client clock lags the server.
+ */
+internal fun sortMessagesForChatDisplay(messages: List<Message>): List<Message> {
+    if (messages.size <= 1) return messages
+    val (pending, confirmed) = messages.partition { it.id < 0 }
+    val comparator = compareBy<Message>(
+        { messageSortEpochMillis(it) },
+        { it.id.toLong() },
+    )
+    return confirmed.sortedWith(comparator) + pending.sortedWith(comparator)
+}
+
+internal fun messageSortEpochMillis(message: Message): Long =
+    parseMessageTimestampMillis(message.timestamp) ?: Long.MIN_VALUE

app/shared/src/commonMain/kotlin/ru/fromchat/api/MessageTimestamps.kt

@@ -0,0 +1,55 @@
+package ru.fromchat.api
+
+import kotlinx.datetime.Instant
+import kotlinx.datetime.LocalDateTime
+import kotlinx.datetime.TimeZone
+import kotlinx.datetime.toLocalDateTime
+import kotlin.time.Clock
+
+private val OFFSET_SUFFIX = Regex("""[+-]\d{2}:\d{2}$""")
+
+/** ISO-8601 UTC instant for new/queued messages. */
+fun nowMessageTimestampIso(): String = Clock.System.now().toString()
+
+/**
+ * Parse message timestamps from server or client.
+ * Zone-less ISO strings are treated as UTC, then shown in the device zone.
+ */
+internal fun parseMessageInstant(timestamp: String): Instant? {
+    val raw = timestamp.trim()
+    if (raw.isEmpty()) return null
+    val normalized = raw.replace(' ', 'T')
+    parseInstantOrNull(normalized)?.let { return it }
+    if (!hasExplicitOffset(normalized)) {
+        parseInstantOrNull("${normalized}Z")?.let { return it }
+    }
+    return null
+}
+
+internal fun parseMessageTimestampMillis(timestamp: String): Long? =
+    parseMessageInstant(timestamp)?.toEpochMilliseconds()
+
+/** HH:mm in the device time zone (bubble footer). */
+internal fun formatMessageTimeLocal(timestamp: String): String {
+    val local = parseMessageInstant(timestamp)?.toDeviceLocal() ?: return ""
+    return "${local.hour.toString().padStart(2, '0')}:${local.minute.toString().padStart(2, '0')}"
+}
+
+/** MM/dd/yyyy HH:mm in the device time zone (fullscreen header). */
+internal fun formatMessageDateTimeLocal(timestamp: String): String {
+    val local = parseMessageInstant(timestamp)?.toDeviceLocal() ?: return timestamp.trim()
+    val month = local.monthNumber.toString().padStart(2, '0')
+    val day = local.dayOfMonth.toString().padStart(2, '0')
+    val hour = local.hour.toString().padStart(2, '0')
+    val minute = local.minute.toString().padStart(2, '0')
+    return "$month/$day/${local.year} $hour:$minute"
+}
+
+private fun parseInstantOrNull(value: String): Instant? =
+    runCatching { Instant.parse(value) }.getOrNull()
+
+private fun hasExplicitOffset(value: String): Boolean =
+    value.endsWith('Z', ignoreCase = true) || OFFSET_SUFFIX.containsMatchIn(value)
+
+private fun Instant.toDeviceLocal(): LocalDateTime =
+    toLocalDateTime(TimeZone.currentSystemDefault())

app/shared/src/commonMain/kotlin/ru/fromchat/api/Models.kt

@@ -397,6 +397,19 @@ data class WebSocketDeleteMessageRequest(
     val message_id: Int
 )
 
+@Serializable
+data class WebSocketDeleteDmRequest(
+    val id: Int,
+    @SerialName("recipientId") val recipientId: Int,
+)
+
+@Serializable
+data class DmDeletedData(
+    val id: Int,
+    @SerialName("senderId") val senderId: Int,
+    @SerialName("recipientId") val recipientId: Int? = null,
+)
+
 @Serializable
 data class DmTypingData(
     @SerialName("recipientId") val recipientId: Int

app/shared/src/commonMain/kotlin/ru/fromchat/api/OptimisticMessageIds.kt

@@ -0,0 +1,10 @@
+package ru.fromchat.api
+
+/** Stable negative row id for an optimistic / outbox [clientMessageId]. */
+fun optimisticMessageIdForClientMessageId(clientMessageId: String): Int {
+    val hc = clientMessageId.hashCode()
+    val absHc = if (hc == Int.MIN_VALUE) Int.MAX_VALUE else kotlin.math.abs(hc)
+    return -(if (absHc == 0) 1 else absHc)
+}
+
+fun Message.isQueuedOutbound(): Boolean = id < 0

app/shared/src/commonMain/kotlin/ru/fromchat/api/ProfileCache.kt

@@ -1,14 +1,12 @@
 package ru.fromchat.api
 
-import com.pr0gramm3r101.utils.settings.settings
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.SupervisorJob
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.sync.Mutex
 import kotlinx.coroutines.sync.withLock
-import kotlinx.serialization.builtins.ListSerializer
-import kotlinx.serialization.json.Json
+import ru.fromchat.api.db.ProfileCacheStore
 import kotlin.concurrent.Volatile
 
 /**
@@ -29,21 +27,16 @@ fun UserProfile.visibleDisplayName(currentUserId: Int? = null): String? =
     displayName?.trim()?.ifEmpty { null } ?: visibleUsername(currentUserId)
 
 /**
- * In-memory profile cache with disk persistence. [get] reads a volatile snapshot (lock-free).
- * [put] copy-on-writes the map and schedules an async flush of the full list to settings.
+ * In-memory profile cache for the active [ru.fromchat.core.cache.CacheContext] instance,
+ * backed by SQLDelight [profile_cache] per instance partition.
  */
 object ProfileCache {
-    private const val SETTINGS_KEY = "profile_cache_profiles_v1"
-
-    private val json = Json {
-        ignoreUnknownKeys = true
-        isLenient = true
-        encodeDefaults = true
-    }
-
     @Volatile
     private var profiles: Map<Int, UserProfile> = emptyMap()
 
+    @Volatile
+    private var loadedInstanceId: String = ""
+
     private val persistMutex = Mutex()
     private val ioScope = CoroutineScope(SupervisorJob() + Dispatchers.Default)
 
@@ -60,24 +53,26 @@ object ProfileCache {
         }
         val cur = profiles
         profiles = cur + (profile.id to profile)
-        schedulePersist()
+        val instanceId = loadedInstanceId
+        if (instanceId.isNotEmpty()) {
+            ioScope.launch {
+                runCatching { ProfileCacheStore.put(instanceId, profile) }
+            }
+        }
     }
 
-    /**
-     * Removes one user from the cache and persists. Does not clear full API profiles unless
-     * the caller only invokes this for preview cleanup flows.
-     */
     fun remove(userId: Int) {
         val cur = profiles
         if (userId !in cur) return
         profiles = cur - userId
-        schedulePersist()
+        val instanceId = loadedInstanceId
+        if (instanceId.isNotEmpty()) {
+            ioScope.launch {
+                runCatching { ProfileCacheStore.remove(instanceId, userId) }
+            }
+        }
     }
 
-    /**
-     * Drops [isClientPreviewOnly] entries that have no usable identity (blank username and
-     * display name). Avoids persisting or showing stale rows from failed loads / bad merges.
-     */
     fun evictUnusableClientPreview(userId: Int) {
         val p = get(userId) ?: return
         if (!p.isClientPreviewOnly) return
@@ -86,11 +81,6 @@ object ProfileCache {
         if (!hasIdentity) remove(userId)
     }
 
-    /**
-     * Seeds or refreshes a lightweight profile from a DM conversations list [User].
-     * Skips when a full `/user/...` profile is already cached.
-     * Does not write a preview when the API user has no non-blank username (avoids caching empty identity).
-     */
     fun mergeFromDmUser(user: User) {
         val existing = get(user.id)
         if (existing != null && !existing.isClientPreviewOnly) return
@@ -116,8 +106,8 @@ object ProfileCache {
                 suspended = existing?.suspended,
                 suspensionReason = existing?.suspensionReason,
                 deleted = existing?.deleted,
-                isClientPreviewOnly = true
-            )
+                isClientPreviewOnly = true,
+            ),
         )
     }
 
@@ -145,42 +135,38 @@ object ProfileCache {
                 suspended = existing?.suspended,
                 suspensionReason = existing?.suspensionReason,
                 deleted = existing?.deleted,
-                isClientPreviewOnly = true
-            )
+                isClientPreviewOnly = true,
+            ),
         )
     }
 
-    /**
-     * Load stored profiles into memory (merged: existing runtime entries win on id clash).
-     * Call after [ApiClient.loadPersistedData].
-     */
+    fun onActiveInstanceChanged(instanceId: String) {
+        ioScope.launch {
+            persistMutex.withLock {
+                loadedInstanceId = instanceId
+                profiles = if (instanceId.isNotEmpty()) {
+                    runCatching { ProfileCacheStore.loadAllForInstance(instanceId) }.getOrDefault(emptyMap())
+                } else {
+                    emptyMap()
+                }
+                pruneUnusableClientPreviewsLocked()
+            }
+        }
+    }
+
     suspend fun hydrateFromDisk() {
+        val instanceId = ru.fromchat.core.cache.CacheContext.activeInstanceId.value.trim()
         persistMutex.withLock {
-            val raw = settings.getString(SETTINGS_KEY, "").ifBlank { return }
-            runCatching {
-                val list = json.decodeFromString(ListSerializer(UserProfile.serializer()), raw)
-                val usable = list.filter { p ->
-                    when {
-                        !p.isClientPreviewOnly -> true
-                        else ->
-                            p.username.trim().isNotEmpty() ||
-                                !p.displayName.isNullOrBlank()
-                    }
-                }
-                val fromDisk = usable.associateBy { it.id }
-                profiles = fromDisk + profiles
-                if (usable.size < list.size) {
-                    schedulePersist()
-                }
+            loadedInstanceId = instanceId
+            profiles = if (instanceId.isNotEmpty()) {
+                runCatching { ProfileCacheStore.loadAllForInstance(instanceId) }.getOrDefault(emptyMap())
+            } else {
+                emptyMap()
             }
             pruneUnusableClientPreviewsLocked()
         }
     }
 
-    /**
-     * Drops in-memory preview-only rows with no identity (e.g. bad runtime state after a failed merge).
-     * Call only while holding [persistMutex] or from [hydrateFromDisk] inside the lock.
-     */
     private fun pruneUnusableClientPreviewsLocked() {
         val snap = profiles
         val toRemove = snap.filter { (_, p) ->
@@ -194,26 +180,12 @@ object ProfileCache {
             cur = cur - id
         }
         profiles = cur
-        schedulePersist()
     }
 
     suspend fun clear() {
         persistMutex.withLock {
             profiles = emptyMap()
-            settings.putString(SETTINGS_KEY, "")
-        }
-    }
-
-    private fun schedulePersist() {
-        ioScope.launch {
-            persistMutex.withLock {
-                val snap = profiles
-                val blob = json.encodeToString(
-                    ListSerializer(UserProfile.serializer()),
-                    snap.values.toList()
-                )
-                settings.putString(SETTINGS_KEY, blob)
-            }
+            loadedInstanceId = ""
         }
     }
 }

app/shared/src/commonMain/kotlin/ru/fromchat/api/WebSocketManager.kt

@@ -2,6 +2,7 @@ package ru.fromchat.api
 
 import io.ktor.client.plugins.websocket.DefaultClientWebSocketSession
 import io.ktor.client.plugins.websocket.webSocket
+import io.ktor.client.request.header
 import io.ktor.client.request.url
 import io.ktor.http.HttpMethod
 import io.ktor.websocket.Frame
@@ -26,7 +27,9 @@ import kotlinx.serialization.json.jsonObject
 import kotlinx.serialization.json.jsonPrimitive
 import ru.fromchat.AppForeground
 import ru.fromchat.core.Logger
+import ru.fromchat.core.cache.CacheContext
 import ru.fromchat.core.config.Config
+import ru.fromchat.core.instance.InstanceIdGuard
 import kotlin.concurrent.Volatile
 import kotlin.coroutines.coroutineContext
 import kotlin.coroutines.suspendCoroutine
@@ -146,10 +149,14 @@ object WebSocketManager {
                     connecting = true
                     ConnectionStateStore.onConnecting()
 
+                    val instanceId = CacheContext.activeInstanceId.value.trim()
                     ApiClient.http.webSocket(
                         method = HttpMethod.Get,
                         request = {
                             url(wsUrl)
+                            if (instanceId.isNotEmpty()) {
+                                header(InstanceIdGuard.INSTANCE_ID_HEADER, instanceId)
+                            }
                         }
                     ) {
                         reconnectDelayMs = MIN_RECONNECT_DELAY_MS

app/shared/src/commonMain/kotlin/ru/fromchat/api/db/ConversationIds.kt

@@ -0,0 +1,18 @@
+package ru.fromchat.api.db
+
+/** General public group chat (only group for now). Groups use negative ids. */
+const val GENERAL_PUBLIC_GROUP_ID: Int = -1
+
+fun conversationIdForGroup(groupId: Int): String = groupId.toString()
+
+fun conversationIdForDm(otherUserId: Int): String = "dm:$otherUserId"
+
+fun groupIdFromConversationId(conversationId: String): Int? =
+    conversationId.toIntOrNull()?.takeIf { it < 0 }
+
+fun dmOtherUserIdFromConversationId(conversationId: String): Int? =
+    if (conversationId.startsWith("dm:")) {
+        conversationId.removePrefix("dm:").toIntOrNull()
+    } else {
+        null
+    }

app/shared/src/commonMain/kotlin/ru/fromchat/api/db/DmStoredMessageContent.kt

@@ -0,0 +1,173 @@
+package ru.fromchat.api.db
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.json.Json
+import kotlinx.serialization.json.JsonArray
+import kotlinx.serialization.json.JsonObject
+import kotlinx.serialization.json.JsonPrimitive
+import kotlinx.serialization.json.jsonArray
+import kotlinx.serialization.json.jsonObject
+import kotlinx.serialization.json.jsonPrimitive
+import com.pr0gramm3r101.utils.files.PlatformFileSystem
+import ru.fromchat.api.DmEnvelope
+import ru.fromchat.api.Message
+import ru.fromchat.ui.chat.AttachmentMediaLog
+import ru.fromchat.ui.chat.DecryptedImageCache
+
+private val json = Json { ignoreUnknownKeys = true; encodeDefaults = true }
+
+@Serializable
+private data class PersistedDmMessagePayload(
+    @SerialName("text") val text: String,
+    @SerialName("envelope") val envelope: DmEnvelope,
+    @SerialName("fileThumbnails") val fileThumbnails: List<String>? = null,
+    @SerialName("fileAspectRatios") val fileAspectRatios: List<Float>? = null,
+    @SerialName("fileSizes") val fileSizes: List<Long>? = null,
+    @SerialName("fileDimensions") val fileDimensions: List<List<Int>>? = null,
+    @SerialName("isContentCorrupted") val isContentCorrupted: Boolean = false,
+    /** Local decrypted preview file (survives outbox / upload staging cleanup). */
+    @SerialName("localPreviewUri") val localPreviewUri: String? = null,
+)
+
+data class ParsedDmMessageContent(
+    val text: String,
+    val envelope: DmEnvelope? = null,
+    val fileThumbnails: List<String>? = null,
+    val fileAspectRatios: List<Float>? = null,
+    val fileSizes: List<Long>? = null,
+    val fileDimensions: List<Pair<Int, Int>>? = null,
+    val isContentCorrupted: Boolean = false,
+    val localPreviewUri: String? = null,
+)
+
+fun resolveLocalPreviewUri(message: Message): String? {
+    message.pendingFileUri?.takeIf { uri ->
+        DecryptedImageCache.isDecryptedImageCacheUri(uri) && localPreviewFileExists(uri)
+    }?.let { return it }
+    val cid = message.client_message_id?.trim()?.takeIf { it.isNotEmpty() }
+    if (cid != null) {
+        DecryptedImageCache.getCached(message.id, fileIndex = 0, cid)
+            ?.takeIf { localPreviewFileExists(it) }
+            ?.let { return it }
+    }
+    if (message.id > 0) {
+        DecryptedImageCache.getCached(message.id, fileIndex = 0, clientMessageId = null)
+            ?.takeIf { localPreviewFileExists(it) }
+            ?.let { return it }
+    }
+    return null
+}
+
+/**
+ * Layout width/height. Pixel pairs keep [w,h] order (landscape vs portrait).
+ * Do not min/max swap — that forces every landscape 4K image into portrait.
+ */
+internal fun attachmentDimensionsForLayout(w: Int, h: Int): Pair<Int, Int> {
+    if (w <= 0 || h <= 0) return 1 to 1
+    return w to h
+}
+
+internal fun aspectRatioFromDimensionPair(w: Int, h: Int): Float {
+    val (dw, dh) = attachmentDimensionsForLayout(w, h)
+    return dw.toFloat() / dh.toFloat()
+}
+
+private fun localPreviewFileExists(uri: String): Boolean {
+    val path = uri.removePrefix("file://")
+    return path.isNotEmpty() && PlatformFileSystem.exists(path)
+}
+
+fun encodePersistedDmMessage(message: Message): String {
+    val envelope = message.dmEnvelope
+        ?: return message.content
+    if (message.files.isNullOrEmpty()) return message.content
+    val dims = message.fileDimensions?.map { listOf(it.first, it.second) }
+    val payload = PersistedDmMessagePayload(
+        text = message.content,
+        envelope = envelope,
+        fileThumbnails = message.fileThumbnails,
+        fileAspectRatios = message.fileAspectRatios,
+        fileSizes = message.fileSizes,
+        fileDimensions = dims,
+        isContentCorrupted = message.isContentCorrupted,
+        localPreviewUri = resolveLocalPreviewUri(message),
+    )
+    AttachmentMediaLog.persist(
+        "encode",
+        "msgId" to message.id,
+        "clientId" to message.client_message_id,
+        "localPreview" to (payload.localPreviewUri?.take(64) ?: "null"),
+        "dims" to (dims?.firstOrNull()?.joinToString("x") ?: "null"),
+    )
+    return json.encodeToString(payload)
+}
+
+fun parseDmMessageContent(plaintext: String): ParsedDmMessageContent {
+    val trimmed = plaintext.trim()
+    if (trimmed.startsWith("{")) {
+        val isPersistedEnvelope = runCatching {
+            json.parseToJsonElement(trimmed).jsonObject.containsKey("envelope")
+        }.getOrDefault(false)
+        if (isPersistedEnvelope) {
+            return runCatching {
+                val payload = json.decodeFromString<PersistedDmMessagePayload>(trimmed)
+                ParsedDmMessageContent(
+                    text = payload.text,
+                    envelope = payload.envelope,
+                    fileThumbnails = payload.fileThumbnails,
+                    fileAspectRatios = payload.fileAspectRatios,
+                    fileSizes = payload.fileSizes,
+                    fileDimensions = payload.fileDimensions?.mapNotNull { pair ->
+                        if (pair.size >= 2) pair[0] to pair[1] else null
+                    },
+                    isContentCorrupted = payload.isContentCorrupted,
+                    localPreviewUri = payload.localPreviewUri?.takeIf { localPreviewFileExists(it) },
+                )
+            }.getOrElse {
+                ParsedDmMessageContent(text = plaintext)
+            }
+        }
+        return parseLegacyDmContentJson(trimmed)
+    }
+    return ParsedDmMessageContent(text = trimmed)
+}
+
+private fun parseLegacyDmContentJson(plaintext: String): ParsedDmMessageContent {
+    if (!plaintext.startsWith("{")) {
+        return ParsedDmMessageContent(text = plaintext)
+    }
+    return runCatching {
+        val obj = json.parseToJsonElement(plaintext).jsonObject
+        val text = obj["text"]?.jsonPrimitive?.content ?: plaintext
+        val thumbArr = obj["fileThumbnails"]?.jsonArray ?: return@runCatching ParsedDmMessageContent(text)
+        val thumbnails = thumbArr.map { it.jsonPrimitive.content }
+        val arArr = obj["fileAspectRatios"]?.jsonArray
+        val parsed = arArr?.mapNotNull { elem ->
+            val a = elem as? JsonArray ?: return@mapNotNull null
+            if (a.size == 2) {
+                val w = (a.getOrNull(0) as? JsonPrimitive)?.content?.toIntOrNull()
+                val h = (a.getOrNull(1) as? JsonPrimitive)?.content?.toIntOrNull()
+                if (w != null && h != null && h > 0) {
+                    Triple(w, h, aspectRatioFromDimensionPair(w, h))
+                } else {
+                    null
+                }
+            } else {
+                null
+            }
+        }?.takeIf { it.size == thumbnails.size }
+        val sizesArr = obj["fileSizes"]?.jsonArray
+        val fileSizes = sizesArr?.mapNotNull { (it as? JsonPrimitive)?.content?.toLongOrNull() }
+            ?.takeIf { it.size == thumbnails.size }
+        ParsedDmMessageContent(
+            text = text,
+            fileThumbnails = thumbnails.ifEmpty { null },
+            fileAspectRatios = parsed?.map { it.third },
+            fileSizes = fileSizes,
+            fileDimensions = parsed?.map { it.first to it.second },
+        )
+    }.getOrElse {
+        ParsedDmMessageContent(text = plaintext)
+    }
+}

app/shared/src/commonMain/kotlin/ru/fromchat/api/db/InstanceRegistryStore.kt

@@ -0,0 +1,111 @@
+package ru.fromchat.api.db
+
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import kotlin.time.Clock
+import ru.fromchat.core.ServerConfigData
+import ru.fromchat.core.cache.CacheContext
+import ru.fromchat.core.configKey
+import ru.fromchat.api.outbox.cancelOutboxProcessing
+import ru.fromchat.ui.chat.PublicChatPanelCache
+import ru.fromchat.ui.dm.DmPanelCache
+
+object InstanceRegistryStore {
+    private val db get() = MessageDatabaseProvider.database
+
+    private fun nowIso(): String = Clock.System.now().toString()
+
+    suspend fun getActiveInstanceIdForConfig(config: ServerConfigData): String? =
+        withContext(Dispatchers.Default) {
+            MessageDatabaseProvider.withDatabaseRecover {
+                db.messageDatabaseQueries
+                    .selectActiveInstanceIdForConfig(config.configKey())
+                    .executeAsOneOrNull()
+            }
+        }
+
+    suspend fun registerInstanceEncountered(instanceId: String) {
+        val id = instanceId.trim()
+        if (id.isEmpty()) return
+        val now = nowIso()
+        withContext(Dispatchers.Default) {
+            MessageDatabaseProvider.withDatabaseRecover {
+                val existing = db.messageDatabaseQueries
+                    .selectAllInstanceIds()
+                    .executeAsList()
+                    .any { it.equals(id, ignoreCase = true) }
+                if (existing) {
+                    db.messageDatabaseQueries.touchInstanceRegistry(now, id)
+                } else {
+                    db.messageDatabaseQueries.upsertInstanceRegistry(id, now, now)
+                }
+            }
+        }
+    }
+
+    suspend fun rebindServerInstance(config: ServerConfigData, newInstanceId: String) {
+        val newId = newInstanceId.trim()
+        require(newId.isNotEmpty())
+        val previousActive = CacheContext.activeInstanceId.value.trim()
+        if (previousActive.isNotEmpty() && !previousActive.equals(newId, ignoreCase = true)) {
+            cancelOutboxProcessing(previousActive)
+        }
+        val key = config.configKey()
+        val now = nowIso()
+        withContext(Dispatchers.Default) {
+            MessageDatabaseProvider.withDatabaseRecover {
+                db.messageDatabaseQueries.upsertServerBinding(key, newId, now)
+                val existing = db.messageDatabaseQueries
+                    .selectAllInstanceIds()
+                    .executeAsList()
+                    .any { it.equals(newId, ignoreCase = true) }
+                if (existing) {
+                    db.messageDatabaseQueries.touchInstanceRegistry(now, newId)
+                } else {
+                    db.messageDatabaseQueries.upsertInstanceRegistry(newId, now, now)
+                }
+            }
+        }
+        val userId = CacheContext.activeUserId.value
+        CacheContext.setActiveInstance(newId, userId)
+        PublicChatPanelCache.clear()
+        DmPanelCache.clearAll()
+    }
+
+    suspend fun rebindServerInstanceOnMismatch(
+        config: ServerConfigData,
+        previousId: String?,
+        fetchedId: String,
+    ) {
+        val prev = previousId?.trim().orEmpty()
+        val next = fetchedId.trim()
+        if (prev.isEmpty() || prev.equals(next, ignoreCase = true)) {
+            rebindServerInstance(config, next)
+            return
+        }
+        rebindServerInstance(config, next)
+    }
+
+    /** User-initiated clear for one instance partition. */
+    suspend fun purgePartition(instanceId: String) {
+        val id = instanceId.trim()
+        if (id.isEmpty()) return
+        withContext(Dispatchers.Default) {
+            MessageDatabaseProvider.withDatabaseRecover {
+                db.messageDatabaseQueries.deleteAllMessagesForInstance(id)
+                db.messageDatabaseQueries.deleteAllConversationsForInstance(id)
+                db.messageDatabaseQueries.deleteAllOutboxForInstance(id)
+                db.messageDatabaseQueries.deleteAllAttachmentsForInstance(id)
+                db.messageDatabaseQueries.deleteAllProfilesForInstance(id)
+            }
+        }
+    }
+
+    suspend fun purgeAllCache() {
+        withContext(Dispatchers.Default) {
+            MessageDatabaseProvider.withDatabaseRecover {
+                db.messageDatabaseQueries.purgeAllCache()
+            }
+        }
+    }
+}

app/shared/src/commonMain/kotlin/ru/fromchat/api/db/LocalCacheWipe.kt

@@ -0,0 +1,26 @@
+package ru.fromchat.api.db
+
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import ru.fromchat.api.outbox.cancelOutboxProcessing
+import ru.fromchat.core.cache.CacheContext
+import ru.fromchat.core.cache.wipeFromChatCacheDirectory
+import ru.fromchat.ui.chat.PublicChatPanelCache
+import ru.fromchat.ui.dm.DmPanelCache
+
+/**
+ * Drops the on-disk FromChat cache tree and reopens SQLite on next access.
+ * Call [writeFromChatCacheGeneration] after this when wiping from settings.
+ */
+suspend fun wipeLocalCacheOnDisk() {
+    val instanceId = runCatching { CacheContext.activeInstanceId.value.trim() }.getOrDefault("")
+    if (instanceId.isNotEmpty()) {
+        cancelOutboxProcessing(instanceId)
+    }
+    withContext(Dispatchers.Default) {
+        MessageDatabaseProvider.closeAndReset()
+    }
+    wipeFromChatCacheDirectory()
+    PublicChatPanelCache.clear()
+    DmPanelCache.clearAll()
+}

app/shared/src/commonMain/kotlin/ru/fromchat/api/db/MessageCacheStore.kt

@@ -1,21 +1,28 @@
 package ru.fromchat.api.db
 
+import app.cash.sqldelight.coroutines.asFlow
+import app.cash.sqldelight.coroutines.mapToList
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.withContext
+import kotlinx.serialization.json.Json
 import ru.fromchat.api.ApiClient
 import ru.fromchat.api.DmConversation
 import ru.fromchat.api.Message
+import ru.fromchat.api.sortMessagesForChatDisplay
+import ru.fromchat.ui.chat.DecryptedImageCache
+import ru.fromchat.ui.chat.dedupeMessagesByClientId
+import ru.fromchat.ui.chat.dropSupersededOptimisticMessages
 import ru.fromchat.api.ProfileCache
+import ru.fromchat.api.outbox.DmAttachmentOutboxPayload
+import ru.fromchat.api.outbox.OutgoingMessageCoordinator
+import ru.fromchat.core.cache.CacheContext
+import ru.fromchat.core.cache.CacheValidator
 import ru.fromchat.db.Conversation
 import ru.fromchat.db.MessageDatabase
 import ru.fromchat.db.Message as DbMessage
 
-/**
- * Simple repository wrapping [MessageDatabase] for caching messages and conversations.
- *
- * This is intentionally minimal – it focuses on the flows the app needs for
- * public chat and DMs rather than trying to mirror the entire backend schema.
- */
 data class CachedConversation(
     val id: String,
     val otherUserId: Int,
@@ -26,16 +33,11 @@ data class CachedConversation(
 
 object MessageCacheStore {
     private val db: MessageDatabase get() = MessageDatabaseProvider.database
+    private val outboxJson = Json { ignoreUnknownKeys = true; encodeDefaults = true }
 
-    private fun conversationIdForPublic(): String = "public"
-    private fun conversationIdForDm(otherUserId: Int): String = "dm:$otherUserId"
+    private fun instanceId(): String = CacheContext.requireActiveInstanceId()
 
-    private fun otherUserIdFromDmConversationId(conversationId: String): Int? =
-        if (conversationId.startsWith("dm:")) {
-            conversationId.removePrefix("dm:").toIntOrNull()
-        } else {
-            null
-        }
+    private fun conversationIdForPublic(): String = conversationIdForGroup(GENERAL_PUBLIC_GROUP_ID)
 
     private fun truncateDmListPreview(text: String, maxLen: Int = 120): String {
         val t = text.trim()
@@ -43,73 +45,48 @@ object MessageCacheStore {
         return if (t.length > maxLen) t.take(maxLen) + "\u2026" else t
     }
 
-    /** Sets [Conversation.lastMessagePreview] from the latest cached plaintext row (DMs are encrypted on the API). */
-    private suspend fun syncDmConversationPreviewFromCache(otherUserId: Int) {
-        val convId = conversationIdForDm(otherUserId)
-        withContext(Dispatchers.Default) {
-            val row = db.messageDatabaseQueries.selectConversations().executeAsList()
-                .find { it.id == convId } ?: return@withContext
-            val recent = db.messageDatabaseQueries
-                .selectRecentMessagesByConversation(convId, 1)
-                .executeAsList()
-                .firstOrNull()
-            val rawPreview = recent?.content?.orEmpty()?.trim().orEmpty()
-            val preview = rawPreview.takeIf { it.isNotEmpty() }
-                ?.let { truncateDmListPreview(it) }
-                ?.takeIf { it.isNotEmpty() }
-            db.messageDatabaseQueries.upsertConversation(
-                id = row.id,
-                type = row.type,
-                otherUserId = row.otherUserId,
-                displayName = row.displayName,
-                lastMessageId = row.lastMessageId,
-                lastMessagePreview = preview,
-                unreadCount = row.unreadCount,
-                updatedAt = row.updatedAt
-            )
-        }
-    }
+    fun observeMessages(instanceId: String, conversationId: String): Flow<List<Message>> =
+        db.messageDatabaseQueries
+            .selectMessagesByConversation(instanceId, conversationId)
+            .asFlow()
+            .mapToList(Dispatchers.Default)
+            .map { rows ->
+                val raw = rows.map { it.toAppMessage() }
+                val withoutSuperseded = dropSupersededOptimisticMessages(raw, ApiClient.user?.id)
+                sortMessagesForChatDisplay(
+                    validatedOrEmpty(
+                        conversationId,
+                        dedupeMessagesByClientId(
+                            enrichQueuedOutboundUi(withoutSuperseded, conversationId),
+                        ),
+                    ),
+                )
+            }
 
-    /**
-     * Full history for a conversation (unbounded). Prefer [loadRecentPublicMessages] when opening UI.
-     */
-    suspend fun loadPublicMessages(): List<Message> {
-        return loadMessages(conversationIdForPublic())
-    }
+    suspend fun loadPublicMessages(): List<Message> =
+        loadMessages(conversationIdForPublic())
 
-    /**
-     * Most recent [limit] messages for public chat, chronological (oldest → newest).
-     * Avoids reading the entire `"public"` thread from SQLite when the cache has grown large.
-     */
-    suspend fun loadRecentPublicMessages(limit: Long): List<Message> {
-        return loadRecentMessages(conversationIdForPublic(), limit)
-    }
+    suspend fun loadRecentPublicMessages(limit: Long): List<Message> =
+        loadRecentMessages(conversationIdForPublic(), limit)
 
     suspend fun replacePublicMessages(messages: List<Message>) {
-        val pending = loadPendingMessages(conversationIdForPublic())
+        val convId = conversationIdForPublic()
+        val pending = loadPendingMessages(convId)
         val stillPending = pending.filter { p ->
             val cid = p.client_message_id
             cid == null || messages.none { it.client_message_id == cid }
         }
-        val merged = (messages + stillPending)
-            .distinctBy { msg ->
-                when {
-                    msg.id > 0 -> "i:${msg.id}"
-                    msg.client_message_id != null -> "c:${msg.client_message_id}"
-                    else -> "i:${msg.id}"
-                }
-            }
-            .sortedBy { it.timestamp }
-        replaceMessages(conversationIdForPublic(), merged)
+        val merged = dedupeMessagesByClientId(messages + stillPending)
+            .let { sortMessagesForChatDisplay(it) }
+        replaceMessages(convId, merged)
     }
 
     suspend fun clearPublicMessages() {
         clearConversationMessages(conversationIdForPublic())
     }
 
-    suspend fun loadDmMessages(otherUserId: Int): List<Message> {
-        return loadMessages(conversationIdForDm(otherUserId))
-    }
+    suspend fun loadDmMessages(otherUserId: Int): List<Message> =
+        loadMessages(conversationIdForDm(otherUserId))
 
     suspend fun clearDmMessages(otherUserId: Int) {
         clearConversationMessages(conversationIdForDm(otherUserId))
@@ -118,22 +95,50 @@ object MessageCacheStore {
     suspend fun replaceDmMessages(otherUserId: Int, messages: List<Message>) {
         val convId = conversationIdForDm(otherUserId)
         val pending = loadPendingMessages(convId)
-        val stillPending = pending.filter { p ->
-            val cid = p.client_message_id
-            cid == null || messages.none { it.client_message_id == cid }
+        val stillPending = filterStillPendingForReplace(convId, pending, messages)
+        val before = messages + stillPending
+        val merged = dedupeMessagesByClientId(
+            dropSupersededOptimisticMessages(before, ApiClient.user?.id),
+        ).let { sortMessagesForChatDisplay(it) }
+        val iid = instanceId()
+        withContext(Dispatchers.Default) {
+            purgeSupersededPendingRows(iid, convId, before, merged)
         }
-        val merged = (messages + stillPending)
-            .distinctBy { msg ->
-                when {
-                    msg.id > 0 -> "i:${msg.id}"
-                    msg.client_message_id != null -> "c:${msg.client_message_id}"
-                    else -> "i:${msg.id}"
-                }
-            }
-            .sortedBy { it.timestamp }
         replaceMessages(convId, merged)
     }
 
+    private suspend fun filterStillPendingForReplace(
+        conversationId: String,
+        pending: List<Message>,
+        messages: List<Message>,
+    ): List<Message> {
+        val selfId = ApiClient.user?.id
+        val selfHasConfirmedAttachment = messages.any { msg ->
+            msg.id > 0 && msg.user_id == selfId && !msg.files.isNullOrEmpty()
+        }
+        val loneSelfPending = pending.count { it.id < 0 && it.user_id == selfId } == 1
+        return pending.filter { p ->
+            val cid = p.client_message_id?.trim().orEmpty()
+            if (cid.isNotEmpty()) {
+                if (hasSentMessageWithClientId(conversationId, cid)) return@filter false
+                if (messages.any { it.id > 0 && it.client_message_id == cid }) return@filter false
+            }
+            val ghostTextOnly = p.id < 0 &&
+                p.files.isNullOrEmpty() &&
+                p.pendingFileUri.isNullOrBlank() &&
+                p.uploadJobId.isNullOrBlank()
+            if (
+                ghostTextOnly &&
+                selfHasConfirmedAttachment &&
+                loneSelfPending &&
+                p.user_id == selfId
+            ) {
+                return@filter false
+            }
+            cid.isEmpty() || messages.none { it.client_message_id == cid }
+        }
+    }
+
     suspend fun upsertPublicMessage(message: Message) {
         upsertSingle(conversationIdForPublic(), message)
     }
@@ -151,6 +156,14 @@ object MessageCacheStore {
         deleteByClientMessageId(conversationIdForDm(otherUserId), clientMessageId)
     }
 
+    suspend fun deleteDmMessageById(otherUserId: Int, messageId: Int) {
+        deleteMessageById(conversationIdForDm(otherUserId), messageId)
+    }
+
+    suspend fun deleteMessageByClientMessageId(conversationId: String, clientMessageId: String) {
+        deleteByClientMessageId(conversationId, clientMessageId)
+    }
+
     suspend fun confirmPublicMessage(clientMessageId: String, confirmed: Message) {
         confirmMessage(conversationIdForPublic(), clientMessageId, confirmed)
     }
@@ -159,138 +172,43 @@ object MessageCacheStore {
         confirmMessage(conversationIdForDm(otherUserId), clientMessageId, confirmed)
     }
 
-    private suspend fun clearConversationMessages(conversationId: String) {
-        withContext(Dispatchers.Default) {
-            db.messageDatabaseQueries.deleteMessagesForConversation(conversationId)
-        }
-    }
-
-    private suspend fun deleteByClientMessageId(conversationId: String, clientMessageId: String) {
-        withContext(Dispatchers.Default) {
-            db.messageDatabaseQueries.deleteMessageByClientMessageId(conversationId, clientMessageId)
-        }
-    }
-
-    private suspend fun upsertSingle(conversationId: String, msg: Message) {
+    /** After decrypt, persist [localPreviewUri] so reopen skips network. */
+    suspend fun patchDmMessageLocalPreview(
+        otherUserId: Int,
+        messageId: Int,
+        localPreviewUri: String,
+    ) {
+        if (messageId <= 0 || !DecryptedImageCache.isDecryptedImageCacheUri(localPreviewUri)) return
+        val convId = conversationIdForDm(otherUserId)
+        val iid = instanceId()
         withContext(Dispatchers.Default) {
+            val row = db.messageDatabaseQueries
+                .selectMessageById(iid, convId, messageId.toLong())
+                .executeAsOneOrNull() ?: return@withContext
+            val msg = row.toAppMessage().copy(pendingFileUri = localPreviewUri)
+            if (msg.files.isNullOrEmpty() || msg.dmEnvelope == null) return@withContext
             db.messageDatabaseQueries.upsertMessage(
+                instanceId = iid,
                 id = msg.id.toLong(),
-                conversationId = conversationId,
+                conversationId = convId,
                 userId = msg.user_id.toLong(),
-                content = msg.content,
+                content = encodePersistedDmMessage(msg),
                 timestamp = msg.timestamp,
                 isRead = if (msg.is_read) 1L else 0L,
                 isEdited = if (msg.is_edited) 1L else 0L,
                 replyToId = msg.reply_to?.id?.toLong(),
                 clientMessageId = msg.client_message_id,
-                deletedFlag = 0L
+                deletedFlag = 0L,
+                sendStatus = "sent",
             )
         }
     }
 
-    private suspend fun confirmMessage(conversationId: String, clientMessageId: String, confirmed: Message) {
-        withContext(Dispatchers.Default) {
-            db.messageDatabaseQueries.transaction {
-                db.messageDatabaseQueries.deleteMessageByClientMessageId(conversationId, clientMessageId)
-                db.messageDatabaseQueries.upsertMessage(
-                    id = confirmed.id.toLong(),
-                    conversationId = conversationId,
-                    userId = confirmed.user_id.toLong(),
-                    content = confirmed.content,
-                    timestamp = confirmed.timestamp,
-                    isRead = if (confirmed.is_read) 1L else 0L,
-                    isEdited = if (confirmed.is_edited) 1L else 0L,
-                    replyToId = confirmed.reply_to?.id?.toLong(),
-                    clientMessageId = confirmed.client_message_id,
-                    deletedFlag = 0L
-                )
-            }
-        }
-        otherUserIdFromDmConversationId(conversationId)?.let { syncDmConversationPreviewFromCache(it) }
-    }
-
-    private suspend fun loadMessages(conversationId: String): List<Message> =
-        withContext(Dispatchers.Default) {
-            db.messageDatabaseQueries
-                .selectMessagesByConversation(conversationId)
-                .executeAsList()
-                .map { row: DbMessage -> row.toAppMessage() }
-        }
-
-    private suspend fun loadRecentMessages(conversationId: String, limit: Long): List<Message> =
-        withContext(Dispatchers.Default) {
-            db.messageDatabaseQueries
-                .selectRecentMessagesByConversation(conversationId, limit)
-                .executeAsList()
-                .map { row: DbMessage -> row.toAppMessage() }
-                .reversed()
-        }
-
-    private suspend fun loadPendingMessages(conversationId: String): List<Message> =
-        withContext(Dispatchers.Default) {
-            db.messageDatabaseQueries
-                .selectPendingMessagesByConversation(conversationId)
-                .executeAsList()
-                .map { row: DbMessage -> row.toAppMessage() }
-        }
-
-    private fun DbMessage.toAppMessage(): Message {
-        val uid = userId.toInt()
-        val self = ApiClient.user
-        val profile = ProfileCache.get(uid)
-        val usernameResolved = when {
-            self != null && uid == self.id -> self.username
-            else -> profile?.username?.takeIf { it.isNotBlank() }
-                ?: profile?.displayName?.takeIf { it.isNotBlank() }
-                ?: ""
-        }
-        val pictureResolved = when {
-            self != null && uid == self.id -> self.profile_picture
-            else -> profile?.profilePicture?.takeIf { it.isNotBlank() }
-        }
-        return Message(
-            id = id.toInt(),
-            user_id = uid,
-            content = content,
-            timestamp = timestamp,
-            is_read = isRead != 0L,
-            is_edited = isEdited != 0L,
-            username = usernameResolved,
-            profile_picture = pictureResolved,
-            verified = profile?.verified,
-            reply_to = null,
-            client_message_id = clientMessageId,
-            reactions = null,
-            files = null
-        )
-    }
-
-    private suspend fun replaceMessages(conversationId: String, messages: List<Message>) {
-        withContext(Dispatchers.Default) {
-            db.messageDatabaseQueries.transaction {
-                db.messageDatabaseQueries.deleteMessagesForConversation(conversationId)
-                messages.forEach { msg ->
-                    db.messageDatabaseQueries.upsertMessage(
-                        id = msg.id.toLong(),
-                        conversationId = conversationId,
-                        userId = msg.user_id.toLong(),
-                        content = msg.content,
-                        timestamp = msg.timestamp,
-                        isRead = if (msg.is_read) 1L else 0L,
-                        isEdited = if (msg.is_edited) 1L else 0L,
-                        replyToId = msg.reply_to?.id?.toLong(),
-                        clientMessageId = msg.client_message_id,
-                        deletedFlag = 0L
-                    )
-                }
-            }
-        }
-        otherUserIdFromDmConversationId(conversationId)?.let { syncDmConversationPreviewFromCache(it) }
-    }
-
     suspend fun markMessageDeleted(conversationId: String, messageId: Int) {
+        val iid = instanceId()
         withContext(Dispatchers.Default) {
             db.messageDatabaseQueries.markMessageDeleted(
+                instanceId = iid,
                 id = messageId.toLong(),
                 conversationId = conversationId
             )
@@ -298,6 +216,7 @@ object MessageCacheStore {
     }
 
     suspend fun replaceDmConversations(conversations: List<DmConversation>) {
+        val iid = instanceId()
         withContext(Dispatchers.Default) {
             db.messageDatabaseQueries.transaction {
                 conversations.forEach { conv ->
@@ -305,7 +224,7 @@ object MessageCacheStore {
                     val displayLabel = conv.user.displayName?.trim()?.takeIf { it.isNotEmpty() }
                         ?: conv.user.username.trim()
                     val recent = db.messageDatabaseQueries
-                        .selectRecentMessagesByConversation(conversationId, 1)
+                        .selectRecentMessagesByConversation(iid, conversationId, 1)
                         .executeAsList()
                         .firstOrNull()
                     val rawPreview = recent?.content?.orEmpty()?.trim().orEmpty()
@@ -313,6 +232,7 @@ object MessageCacheStore {
                         ?.let { truncateDmListPreview(it) }
                         ?.takeIf { it.isNotEmpty() }
                     db.messageDatabaseQueries.upsertConversation(
+                        instanceId = iid,
                         id = conversationId,
                         type = "dm",
                         otherUserId = conv.user.id.toLong(),
@@ -330,7 +250,7 @@ object MessageCacheStore {
     suspend fun loadCachedDmConversations(): List<CachedConversation> =
         withContext(Dispatchers.Default) {
             db.messageDatabaseQueries
-                .selectConversations()
+                .selectConversationsForInstance(instanceId())
                 .executeAsList()
                 .filter { row: Conversation -> row.type == "dm" }
                 .map { row: Conversation ->
@@ -343,5 +263,343 @@ object MessageCacheStore {
                     )
                 }
         }
-}
 
+    private suspend fun syncDmConversationPreviewFromCache(otherUserId: Int) {
+        val iid = instanceId()
+        val convId = conversationIdForDm(otherUserId)
+        withContext(Dispatchers.Default) {
+            val row = db.messageDatabaseQueries
+                .selectConversationsForInstance(iid)
+                .executeAsList()
+                .find { it.id == convId } ?: return@withContext
+            val recent = db.messageDatabaseQueries
+                .selectRecentMessagesByConversation(iid, convId, 1)
+                .executeAsList()
+                .firstOrNull()
+            val rawPreview = recent?.content?.orEmpty()?.trim().orEmpty()
+            val preview = rawPreview.takeIf { it.isNotEmpty() }
+                ?.let { truncateDmListPreview(it) }
+                ?.takeIf { it.isNotEmpty() }
+            db.messageDatabaseQueries.upsertConversation(
+                instanceId = iid,
+                id = row.id,
+                type = row.type,
+                otherUserId = row.otherUserId,
+                displayName = row.displayName,
+                lastMessageId = row.lastMessageId,
+                lastMessagePreview = preview,
+                unreadCount = row.unreadCount,
+                updatedAt = row.updatedAt
+            )
+        }
+    }
+
+    private suspend fun clearConversationMessages(conversationId: String) {
+        val iid = instanceId()
+        withContext(Dispatchers.Default) {
+            db.messageDatabaseQueries.deleteMessagesForConversation(iid, conversationId)
+        }
+    }
+
+    private suspend fun deleteByClientMessageId(conversationId: String, clientMessageId: String) {
+        val iid = instanceId()
+        withContext(Dispatchers.Default) {
+            db.messageDatabaseQueries.deleteMessageByClientMessageId(iid, conversationId, clientMessageId)
+        }
+    }
+
+    private suspend fun deleteMessageById(conversationId: String, messageId: Int) {
+        val iid = instanceId()
+        withContext(Dispatchers.Default) {
+            db.messageDatabaseQueries.deleteMessageById(
+                instanceId = iid,
+                conversationId = conversationId,
+                id = messageId.toLong(),
+            )
+        }
+    }
+
+    private suspend fun upsertSingle(conversationId: String, msg: Message) {
+        val iid = instanceId()
+        withContext(Dispatchers.Default) {
+            db.messageDatabaseQueries.upsertMessage(
+                instanceId = iid,
+                id = msg.id.toLong(),
+                conversationId = conversationId,
+                userId = msg.user_id.toLong(),
+                content = msg.content,
+                timestamp = msg.timestamp,
+                isRead = if (msg.is_read) 1L else 0L,
+                isEdited = if (msg.is_edited) 1L else 0L,
+                replyToId = msg.reply_to?.id?.toLong(),
+                clientMessageId = msg.client_message_id,
+                deletedFlag = 0L,
+                sendStatus = if (msg.id < 0) "pending" else "sent"
+            )
+        }
+    }
+
+    private suspend fun confirmMessage(conversationId: String, clientMessageId: String, confirmed: Message) {
+        val iid = instanceId()
+        val storedContent = encodePersistedDmMessage(confirmed)
+        withContext(Dispatchers.Default) {
+            db.messageDatabaseQueries.transaction {
+                db.messageDatabaseQueries.deleteMessageByClientMessageId(iid, conversationId, clientMessageId)
+                db.messageDatabaseQueries.upsertMessage(
+                    instanceId = iid,
+                    id = confirmed.id.toLong(),
+                    conversationId = conversationId,
+                    userId = confirmed.user_id.toLong(),
+                    content = storedContent,
+                    timestamp = confirmed.timestamp,
+                    isRead = if (confirmed.is_read) 1L else 0L,
+                    isEdited = if (confirmed.is_edited) 1L else 0L,
+                    replyToId = confirmed.reply_to?.id?.toLong(),
+                    clientMessageId = confirmed.client_message_id,
+                    deletedFlag = 0L,
+                    sendStatus = "sent"
+                )
+            }
+        }
+        dmOtherUserIdFromConversationId(conversationId)?.let { syncDmConversationPreviewFromCache(it) }
+    }
+
+    private suspend fun loadMessages(conversationId: String): List<Message> {
+        val iid = instanceId()
+        OutgoingMessageCoordinator.pruneStaleAttachmentOutboxForInstance(iid)
+        return withContext(Dispatchers.Default) {
+            val raw = db.messageDatabaseQueries
+                .selectMessagesByConversation(iid, conversationId)
+                .executeAsList()
+                .map { row: DbMessage -> row.toAppMessage() }
+            val withoutSuperseded = dropSupersededOptimisticMessages(raw, ApiClient.user?.id)
+            purgeSupersededPendingRows(iid, conversationId, raw, withoutSuperseded)
+            sortMessagesForChatDisplay(
+                validatedOrEmpty(
+                    conversationId,
+                    dedupeMessagesByClientId(
+                        enrichQueuedOutboundUi(withoutSuperseded, conversationId),
+                    ),
+                ),
+            )
+        }
+    }
+
+    private suspend fun loadRecentMessages(conversationId: String, limit: Long): List<Message> {
+        val iid = instanceId()
+        return withContext(Dispatchers.Default) {
+            db.messageDatabaseQueries
+                .selectRecentMessagesByConversation(iid, conversationId, limit)
+                .executeAsList()
+                .map { row: DbMessage -> row.toAppMessage() }
+                .reversed()
+        }
+    }
+
+    private suspend fun loadPendingMessages(conversationId: String): List<Message> {
+        val iid = instanceId()
+        return withContext(Dispatchers.Default) {
+            db.messageDatabaseQueries
+                .selectPendingMessagesByConversation(iid, conversationId)
+                .executeAsList()
+                .map { row: DbMessage -> row.toAppMessage() }
+                .filter { row ->
+                    val cid = row.client_message_id?.trim().orEmpty()
+                    cid.isEmpty() ||
+                        db.messageDatabaseQueries
+                            .selectSentMessageIdByClientMessageId(iid, conversationId, cid)
+                            .executeAsOneOrNull() == null
+                }
+                .let { enrichQueuedOutboundUi(it, conversationId) }
+                .let { dedupeMessagesByClientId(it) }
+                .let { sortMessagesForChatDisplay(it) }
+        }
+    }
+
+    private fun enrichQueuedOutboundUi(
+        messages: List<Message>,
+        conversationId: String,
+    ): List<Message> {
+        if (messages.none { it.id < 0 }) return messages
+        val iid = instanceId()
+        val attachmentOutbox = db.messageDatabaseQueries
+            .selectPendingOutboxForInstance(iid)
+            .executeAsList()
+            .filter {
+                it.conversationId == conversationId &&
+                    (
+                        it.kind == OutgoingMessageCoordinator.KIND_SEND_DM_ATTACHMENT ||
+                            it.kind == OutgoingMessageCoordinator.KIND_SEND_DM_ATTACHMENT_AWAITING_ACK
+                        )
+            }
+        if (attachmentOutbox.isEmpty()) return messages
+        val confirmedClientIds = messages
+            .filter { it.id > 0 }
+            .mapNotNull { it.client_message_id?.trim()?.takeIf { cid -> cid.isNotEmpty() } }
+            .toSet()
+        val payloads = attachmentOutbox.associate { row ->
+            row.clientMessageId to runCatching {
+                Triple(
+                    outboxJson.decodeFromString<DmAttachmentOutboxPayload>(row.payloadJson),
+                    row.bytesUploaded,
+                    row.kind,
+                )
+            }.getOrNull()
+        }
+        return messages.mapNotNull { msg ->
+            if (msg.id >= 0) return@mapNotNull msg
+            val cid = msg.client_message_id?.trim().orEmpty()
+            if (cid.isNotEmpty() && cid in confirmedClientIds) return@mapNotNull null
+            if (cid.isEmpty()) return@mapNotNull msg
+            val entry = payloads[cid] ?: return@mapNotNull msg
+            val (payload, bytesUploaded, kind) = entry
+            val uploadFinished = kind == OutgoingMessageCoordinator.KIND_SEND_DM_ATTACHMENT_AWAITING_ACK
+            val totalBytes = when {
+                payload.encryptedFileSizeBytes > 0L -> payload.encryptedFileSizeBytes
+                else -> payload.fileSizeBytes
+            }
+            val percent = when {
+                uploadFinished -> null
+                totalBytes > 0L && bytesUploaded > 0L ->
+                    ((bytesUploaded.toDouble() / totalBytes.toDouble()) * 100.0).toInt().coerceIn(0, 99)
+                bytesUploaded > 0L -> 1
+                else -> msg.uploadProgress ?: 0
+            }
+            msg.copy(
+                pendingFileUri = payload.fileUri,
+                pendingFilename = payload.filename,
+                pendingFileAspectRatio = payload.aspectRatio?.takeIf { it > 0f }
+                    ?: msg.pendingFileAspectRatio,
+                uploadJobId = cid,
+                uploadProgress = percent,
+            )
+        }
+    }
+
+    private fun purgeSupersededPendingRows(
+        instanceId: String,
+        conversationId: String,
+        before: List<Message>,
+        after: List<Message>,
+    ) {
+        val keptIds = after.map { it.id }.toSet()
+        before.filter { it.id < 0 && it.id !in keptIds }.forEach { dropped ->
+            val cid = dropped.client_message_id?.trim().orEmpty()
+            if (cid.isNotEmpty()) {
+                db.messageDatabaseQueries.deletePendingMessageByClientMessageId(
+                    instanceId,
+                    conversationId,
+                    cid,
+                )
+                db.messageDatabaseQueries.deleteOutboxItem(instanceId, cid)
+            }
+        }
+    }
+
+    private fun DbMessage.toAppMessage(): Message {
+        val uid = userId.toInt()
+        val self = ApiClient.user
+        val profile = ProfileCache.get(uid)
+        val usernameResolved = when {
+            self != null && uid == self.id -> self.username
+            else -> profile?.username?.takeIf { it.isNotBlank() }
+                ?: profile?.displayName?.takeIf { it.isNotBlank() }
+                ?: ""
+        }
+        val pictureResolved = when {
+            self != null && uid == self.id -> self.profile_picture
+            else -> profile?.profilePicture?.takeIf { it.isNotBlank() }
+        }
+        val parsed = parseDmMessageContent(content)
+        val base = Message(
+            id = id.toInt(),
+            user_id = uid,
+            content = parsed.text,
+            timestamp = timestamp,
+            is_read = isRead != 0L,
+            is_edited = isEdited != 0L,
+            username = usernameResolved,
+            profile_picture = pictureResolved,
+            verified = profile?.verified,
+            reply_to = null,
+            client_message_id = clientMessageId,
+            reactions = null,
+            files = parsed.envelope?.files,
+            dmEnvelope = parsed.envelope,
+            fileThumbnails = parsed.fileThumbnails,
+            fileAspectRatios = parsed.fileAspectRatios,
+            fileSizes = parsed.fileSizes,
+            fileDimensions = parsed.fileDimensions,
+            isContentCorrupted = parsed.isContentCorrupted,
+        )
+        return base.copy(
+            pendingFileUri = parsed.localPreviewUri ?: resolveLocalPreviewUri(base),
+            pendingFileAspectRatio = parsed.fileAspectRatios?.firstOrNull()
+                ?: parsed.fileDimensions?.firstOrNull()?.let { (w, h) ->
+                    aspectRatioFromDimensionPair(w, h)
+                },
+        )
+    }
+
+    suspend fun clearAll() {
+        withContext(Dispatchers.Default) {
+            db.messageDatabaseQueries.purgeAllCache()
+        }
+    }
+
+    private fun validatedOrEmpty(conversationId: String, messages: List<Message>): List<Message> {
+        val self = ApiClient.user?.id
+        if (!CacheValidator.isConversationCacheCoherent(conversationId, messages, self)) {
+            return emptyList()
+        }
+        return CacheValidator.filterMessages(conversationId, messages, self)
+    }
+
+    private suspend fun replaceMessages(conversationId: String, messages: List<Message>) {
+        val self = ApiClient.user?.id
+        if (!CacheValidator.isConversationCacheCoherent(conversationId, messages, self)) {
+            clearConversationMessages(conversationId)
+            return
+        }
+        val validated = CacheValidator.filterMessages(conversationId, messages, self)
+        val iid = instanceId()
+        withContext(Dispatchers.Default) {
+            db.messageDatabaseQueries.transaction {
+                db.messageDatabaseQueries.deleteMessagesForConversation(iid, conversationId)
+                validated.forEach { msg ->
+                    db.messageDatabaseQueries.upsertMessage(
+                        instanceId = iid,
+                        id = msg.id.toLong(),
+                        conversationId = conversationId,
+                        userId = msg.user_id.toLong(),
+                        content = when {
+                            msg.id < 0 -> msg.content
+                            !msg.files.isNullOrEmpty() && msg.dmEnvelope != null ->
+                                encodePersistedDmMessage(msg)
+                            else -> msg.content
+                        },
+                        timestamp = msg.timestamp,
+                        isRead = if (msg.is_read) 1L else 0L,
+                        isEdited = if (msg.is_edited) 1L else 0L,
+                        replyToId = msg.reply_to?.id?.toLong(),
+                        clientMessageId = msg.client_message_id,
+                        deletedFlag = 0L,
+                        sendStatus = if (msg.id < 0) "pending" else "sent"
+                    )
+                }
+            }
+        }
+        dmOtherUserIdFromConversationId(conversationId)?.let { syncDmConversationPreviewFromCache(it) }
+    }
+
+    suspend fun hasSentMessageWithClientId(conversationId: String, clientMessageId: String): Boolean {
+        val cid = clientMessageId.trim()
+        if (cid.isEmpty()) return false
+        val iid = instanceId()
+        return withContext(Dispatchers.Default) {
+            db.messageDatabaseQueries
+                .selectSentMessageIdByClientMessageId(iid, conversationId, cid)
+                .executeAsOneOrNull() != null
+        }
+    }
+}

app/shared/src/commonMain/kotlin/ru/fromchat/api/db/MessageDatabaseExpectedSchema.kt

@@ -0,0 +1,180 @@
+package ru.fromchat.api.db
+
+/**
+ * Target SQLDelight schema (source of truth for diff). Not a version number — only shape.
+ */
+internal object MessageDatabaseExpectedSchema {
+    val managedTables: Set<String> = setOf(
+        "server_binding",
+        "instance_registry",
+        "conversation",
+        "message",
+        "attachment",
+        "outbox",
+        "profile_cache",
+    )
+
+    val tableCreateSql: Map<String, String> = mapOf(
+        "server_binding" to """
+            CREATE TABLE server_binding (
+                configKey TEXT NOT NULL PRIMARY KEY,
+                activeInstanceId TEXT NOT NULL,
+                updatedAt TEXT
+            )
+        """.trimIndent(),
+        "instance_registry" to """
+            CREATE TABLE instance_registry (
+                instanceId TEXT NOT NULL PRIMARY KEY,
+                firstSeenAt TEXT NOT NULL,
+                lastSeenAt TEXT NOT NULL
+            )
+        """.trimIndent(),
+        "conversation" to """
+            CREATE TABLE conversation (
+                instanceId TEXT NOT NULL,
+                id TEXT NOT NULL,
+                type TEXT NOT NULL,
+                otherUserId INTEGER,
+                displayName TEXT,
+                lastMessageId INTEGER,
+                lastMessagePreview TEXT,
+                unreadCount INTEGER NOT NULL DEFAULT 0,
+                updatedAt TEXT,
+                PRIMARY KEY (instanceId, id)
+            )
+        """.trimIndent(),
+        "message" to """
+            CREATE TABLE message (
+                instanceId TEXT NOT NULL,
+                id INTEGER NOT NULL,
+                conversationId TEXT NOT NULL,
+                userId INTEGER NOT NULL,
+                content TEXT NOT NULL,
+                timestamp TEXT NOT NULL,
+                isRead INTEGER NOT NULL,
+                isEdited INTEGER NOT NULL,
+                replyToId INTEGER,
+                clientMessageId TEXT,
+                deletedFlag INTEGER NOT NULL DEFAULT 0,
+                sendStatus TEXT,
+                PRIMARY KEY (instanceId, conversationId, id)
+            )
+        """.trimIndent(),
+        "attachment" to """
+            CREATE TABLE attachment (
+                instanceId TEXT NOT NULL,
+                id INTEGER NOT NULL,
+                messageId INTEGER NOT NULL,
+                conversationId TEXT NOT NULL,
+                remotePath TEXT,
+                localPath TEXT,
+                status TEXT NOT NULL,
+                blurhash TEXT,
+                aspectRatio REAL,
+                size INTEGER,
+                bytesTransferred INTEGER NOT NULL DEFAULT 0,
+                clientMessageId TEXT,
+                PRIMARY KEY (instanceId, id, messageId, conversationId)
+            )
+        """.trimIndent(),
+        "outbox" to """
+            CREATE TABLE outbox (
+                instanceId TEXT NOT NULL,
+                clientMessageId TEXT NOT NULL,
+                conversationId TEXT NOT NULL,
+                kind TEXT NOT NULL,
+                payloadJson TEXT NOT NULL,
+                retryCount INTEGER NOT NULL DEFAULT 0,
+                nextAttemptAt TEXT,
+                bytesUploaded INTEGER NOT NULL DEFAULT 0,
+                PRIMARY KEY (instanceId, clientMessageId)
+            )
+        """.trimIndent(),
+        "profile_cache" to """
+            CREATE TABLE profile_cache (
+                instanceId TEXT NOT NULL,
+                userId INTEGER NOT NULL,
+                json TEXT NOT NULL,
+                PRIMARY KEY (instanceId, userId)
+            )
+        """.trimIndent(),
+    )
+
+    /** Columns that must exist; value is ALTER TABLE suffix when addable without rebuild. */
+    val requiredColumns: Map<String, Map<String, String>> = mapOf(
+        "server_binding" to mapOf(
+            "configKey" to "TEXT NOT NULL",
+            "activeInstanceId" to "TEXT NOT NULL",
+            "updatedAt" to "TEXT",
+        ),
+        "instance_registry" to mapOf(
+            "instanceId" to "TEXT NOT NULL",
+            "firstSeenAt" to "TEXT NOT NULL",
+            "lastSeenAt" to "TEXT NOT NULL",
+        ),
+        "conversation" to mapOf(
+            "instanceId" to "TEXT NOT NULL",
+            "id" to "TEXT NOT NULL",
+            "type" to "TEXT NOT NULL",
+            "otherUserId" to "INTEGER",
+            "displayName" to "TEXT",
+            "lastMessageId" to "INTEGER",
+            "lastMessagePreview" to "TEXT",
+            "unreadCount" to "INTEGER NOT NULL DEFAULT 0",
+            "updatedAt" to "TEXT",
+        ),
+        "message" to mapOf(
+            "instanceId" to "TEXT NOT NULL",
+            "id" to "INTEGER NOT NULL",
+            "conversationId" to "TEXT NOT NULL",
+            "userId" to "INTEGER NOT NULL",
+            "content" to "TEXT NOT NULL",
+            "timestamp" to "TEXT NOT NULL",
+            "isRead" to "INTEGER NOT NULL",
+            "isEdited" to "INTEGER NOT NULL",
+            "replyToId" to "INTEGER",
+            "clientMessageId" to "TEXT",
+            "deletedFlag" to "INTEGER NOT NULL DEFAULT 0",
+            "sendStatus" to "TEXT",
+        ),
+        "attachment" to mapOf(
+            "instanceId" to "TEXT NOT NULL",
+            "id" to "INTEGER NOT NULL",
+            "messageId" to "INTEGER NOT NULL",
+            "conversationId" to "TEXT NOT NULL",
+            "remotePath" to "TEXT",
+            "localPath" to "TEXT",
+            "status" to "TEXT NOT NULL",
+            "blurhash" to "TEXT",
+            "aspectRatio" to "REAL",
+            "size" to "INTEGER",
+            "bytesTransferred" to "INTEGER NOT NULL DEFAULT 0",
+            "clientMessageId" to "TEXT",
+        ),
+        "outbox" to mapOf(
+            "instanceId" to "TEXT NOT NULL",
+            "clientMessageId" to "TEXT NOT NULL",
+            "conversationId" to "TEXT NOT NULL",
+            "kind" to "TEXT NOT NULL",
+            "payloadJson" to "TEXT NOT NULL",
+            "retryCount" to "INTEGER NOT NULL DEFAULT 0",
+            "nextAttemptAt" to "TEXT",
+            "bytesUploaded" to "INTEGER NOT NULL DEFAULT 0",
+        ),
+        "profile_cache" to mapOf(
+            "instanceId" to "TEXT NOT NULL",
+            "userId" to "INTEGER NOT NULL",
+            "json" to "TEXT NOT NULL",
+        ),
+    )
+
+    /** Tables that require [instanceId]; missing it triggers rebuild-with-copy, not wipe. */
+    val partitionedTables: Set<String> = setOf("message", "conversation", "attachment")
+
+    val requiredIndexes: Map<String, String> = mapOf(
+        "message_instance_conversation_index" to
+            "CREATE INDEX IF NOT EXISTS message_instance_conversation_index ON message(instanceId, conversationId, timestamp)",
+    )
+
+    val obsoleteIndexes: Set<String> = setOf("message_conversation_index")
+}

app/shared/src/commonMain/kotlin/ru/fromchat/api/db/MessageDatabaseLock.kt

@@ -0,0 +1,3 @@
+package ru.fromchat.api.db
+
+internal expect fun <T> withMessageDatabaseLock(block: () -> T): T

app/shared/src/commonMain/kotlin/ru/fromchat/api/db/MessageDatabaseProvider.kt

@@ -9,8 +9,62 @@ import ru.fromchat.db.MessageDatabase
 expect fun provideMessageDatabaseDriver(): SqlDriver
 
 object MessageDatabaseProvider {
-    val database: MessageDatabase by lazy {
-        MessageDatabase(provideMessageDatabaseDriver())
+    private var driver: SqlDriver? = null
+    private var databaseHolder: MessageDatabase? = null
+
+    val database: MessageDatabase
+        get() = withMessageDatabaseLock {
+            databaseHolder ?: MessageDatabase(openDriverLocked()).also { databaseHolder = it }
+        }
+
+    /**
+     * Closes the open SQLite connection. Required before deleting `cacheDir/fromchat/`
+     * (otherwise the next write hits SQLITE_READONLY_DBMOVED).
+     */
+    fun closeAndReset() {
+        withMessageDatabaseLock {
+            databaseHolder = null
+            runCatching { driver?.close() }
+            driver = null
+        }
+    }
+
+    /** Runs [block] once; on a stale connection after cache wipe, resets and retries. */
+    internal fun <T> withDatabaseRecover(block: () -> T): T {
+        return try {
+            block()
+        } catch (e: Exception) {
+            if (!isStaleSqliteConnection(e)) throw e
+            closeAndReset()
+            block()
+        }
+    }
+
+    internal fun isStaleSqliteConnection(throwable: Throwable): Boolean {
+        var current: Throwable? = throwable
+        while (current != null) {
+            val message = current.message?.lowercase().orEmpty()
+            if (message.contains("readonly") && message.contains("database")) return true
+            if (message.contains("sqlite_readonly_dbmoved")) return true
+            current = current.cause
+        }
+        return false
+    }
+
+    fun rebindUnboundPartition(targetInstanceId: String) {
+        runCatching {
+            withMessageDatabaseLock {
+                rebindUnboundMigrationInstance(openDriverLocked(), targetInstanceId)
+            }
+        }
+    }
+
+    /** Caller must hold the message-database lock via [withMessageDatabaseLock]. */
+    private fun openDriverLocked(): SqlDriver {
+        driver?.let { return it }
+        return provideMessageDatabaseDriver().also {
+            ensureMessageDatabaseSchema(it)
+            driver = it
+        }
     }
 }
-

app/shared/src/commonMain/kotlin/ru/fromchat/api/db/MessageDatabaseSchemaGuard.kt

@@ -0,0 +1,486 @@
+package ru.fromchat.api.db
+
+import app.cash.sqldelight.db.QueryResult
+import app.cash.sqldelight.db.SqlDriver
+import kotlinx.coroutines.runBlocking
+import ru.fromchat.core.Settings
+import ru.fromchat.core.instance.isValidInstanceUuid
+
+/**
+ * Aligns on-disk SQLite with [MessageDatabaseExpectedSchema] by structural diff only
+ * (no user_version / schema version buckets). Full wipe is last resort.
+ */
+internal const val UNBOUND_MIGRATION_INSTANCE_ID = "00000000-0000-4000-8000-000000000001"
+
+internal fun ensureMessageDatabaseSchema(driver: SqlDriver) {
+  runCatching { migrateMessageDatabaseSchema(driver) }
+    .onFailure { recreateMessageDatabaseSchema(driver) }
+}
+
+/** Reassign rows stored under [UNBOUND_MIGRATION_INSTANCE_ID] when a real instance id is known. */
+internal fun rebindUnboundMigrationInstance(driver: SqlDriver, targetInstanceId: String) {
+  val target = targetInstanceId.trim()
+  if (target.isEmpty() || !isValidInstanceUuid(target)) return
+  if (target == UNBOUND_MIGRATION_INSTANCE_ID) return
+  if (!tableExists(driver, "message")) return
+  val tablesWithInstance = listOf(
+    "message",
+    "conversation",
+    "attachment",
+    "outbox",
+    "profile_cache",
+  )
+  inTransaction(driver) {
+    for (table in tablesWithInstance) {
+      if (!tableExists(driver, table)) continue
+      if (!columnExists(driver, table, "instanceId")) continue
+      driver.execute(
+        identifier = null,
+        sql = "UPDATE $table SET instanceId = ? WHERE instanceId = ?",
+        parameters = 2,
+        binders = {
+          bindString(0, target)
+          bindString(1, UNBOUND_MIGRATION_INSTANCE_ID)
+        },
+      )
+    }
+  }
+}
+
+private data class ColumnAdd(val table: String, val column: String, val definition: String)
+
+private enum class PartitionedTableRebuild {
+  Message,
+  Conversation,
+  Attachment,
+}
+
+private data class SchemaDiff(
+  val createTables: List<String> = emptyList(),
+  val partitionRebuilds: List<PartitionedTableRebuild> = emptyList(),
+  val addColumns: List<ColumnAdd> = emptyList(),
+  val ensureIndexes: List<Pair<String, String>> = emptyList(),
+  val dropIndexes: Set<String> = emptySet(),
+  val unrecoverableReason: String? = null,
+)
+
+private fun migrateMessageDatabaseSchema(driver: SqlDriver) {
+  val diff = computeSchemaDiff(driver)
+  diff.unrecoverableReason?.let { error(it) }
+  if (diff.isNoOp()) {
+    normalizeLegacyConversationIds(driver)
+    return
+  }
+  applySchemaDiff(driver, diff)
+  normalizeLegacyConversationIds(driver)
+}
+
+private fun SchemaDiff.isNoOp(): Boolean =
+  createTables.isEmpty() &&
+    partitionRebuilds.isEmpty() &&
+    addColumns.isEmpty() &&
+    ensureIndexes.isEmpty() &&
+    dropIndexes.isEmpty()
+
+private fun computeSchemaDiff(driver: SqlDriver): SchemaDiff {
+  val tables = listTables(driver)
+  if (tables.isEmpty()) {
+    return SchemaDiff(
+      createTables = MessageDatabaseExpectedSchema.managedTables.toList(),
+      ensureIndexes = MessageDatabaseExpectedSchema.requiredIndexes.map { it.key to it.value },
+    )
+  }
+
+  var createTables = mutableListOf<String>()
+  var partitionRebuilds = mutableListOf<PartitionedTableRebuild>()
+  var addColumns = mutableListOf<ColumnAdd>()
+  var unrecoverable: String? = null
+
+  fun fail(reason: String) {
+    if (unrecoverable == null) unrecoverable = reason
+  }
+
+  for (tableName in MessageDatabaseExpectedSchema.managedTables) {
+    if (unrecoverable != null) break
+    val required = MessageDatabaseExpectedSchema.requiredColumns[tableName] ?: continue
+    if (!tables.contains(tableName)) {
+      createTables.add(tableName)
+      continue
+    }
+
+    val actual = columnNames(driver, tableName)
+    if (tableName in MessageDatabaseExpectedSchema.partitionedTables && !actual.contains("instanceId")) {
+      if (!legacyPartitionCorePresent(tableName, actual)) {
+        fail("$tableName exists but lacks instanceId and recognizable legacy columns")
+        continue
+      }
+      partitionRebuilds.add(tableName.toPartitionRebuild())
+      continue
+    }
+
+    if (!partitionCorePresent(tableName, actual)) {
+      fail("$tableName is missing required columns: ${required.keys - actual}")
+      continue
+    }
+
+    for ((column, definition) in required) {
+      if (actual.contains(column)) continue
+      if (column == "instanceId") continue
+      addColumns.add(ColumnAdd(tableName, column, definition))
+    }
+  }
+
+  if (unrecoverable != null) {
+    return SchemaDiff(unrecoverableReason = unrecoverable)
+  }
+
+  val ensureIndexes = MessageDatabaseExpectedSchema.requiredIndexes
+    .filterNot { (name, _) -> indexExists(driver, name) }
+    .map { it.key to it.value }
+
+  val dropIndexes = MessageDatabaseExpectedSchema.obsoleteIndexes
+    .filter { indexExists(driver, it) }
+    .toSet()
+
+  return SchemaDiff(
+    createTables = createTables,
+    partitionRebuilds = partitionRebuilds.distinct(),
+    addColumns = addColumns,
+    ensureIndexes = ensureIndexes,
+    dropIndexes = dropIndexes,
+  )
+}
+
+private fun String.toPartitionRebuild(): PartitionedTableRebuild =
+  when (this) {
+    "message" -> PartitionedTableRebuild.Message
+    "conversation" -> PartitionedTableRebuild.Conversation
+    "attachment" -> PartitionedTableRebuild.Attachment
+    else -> error("Not a partitioned table: $this")
+  }
+
+private fun legacyPartitionCorePresent(table: String, actual: Set<String>): Boolean =
+  when (table) {
+    "message" ->
+      actual.containsAll(
+        setOf(
+          "id",
+          "conversationId",
+          "userId",
+          "content",
+          "timestamp",
+          "isRead",
+          "isEdited",
+          "deletedFlag",
+        ),
+      )
+    "conversation" -> actual.containsAll(setOf("id", "type"))
+    "attachment" -> actual.containsAll(setOf("id", "messageId", "conversationId", "status"))
+    else -> false
+  }
+
+private fun partitionCorePresent(table: String, actual: Set<String>): Boolean {
+  val required = MessageDatabaseExpectedSchema.requiredColumns[table] ?: return true
+  val core =
+    when (table) {
+      "message" ->
+        setOf(
+          "instanceId",
+          "id",
+          "conversationId",
+          "userId",
+          "content",
+          "timestamp",
+          "isRead",
+          "isEdited",
+          "deletedFlag",
+        )
+      "conversation" -> setOf("instanceId", "id", "type")
+      "attachment" -> setOf("instanceId", "id", "messageId", "conversationId", "status")
+      "server_binding" -> setOf("configKey", "activeInstanceId")
+      "instance_registry" -> setOf("instanceId", "firstSeenAt", "lastSeenAt")
+      "outbox" ->
+        setOf("instanceId", "clientMessageId", "conversationId", "kind", "payloadJson", "retryCount")
+      "profile_cache" -> setOf("instanceId", "userId", "json")
+      else -> required.keys
+    }
+  return core.all { actual.contains(it) }
+}
+
+private fun applySchemaDiff(driver: SqlDriver, diff: SchemaDiff) {
+  val instanceId = migrationInstanceId()
+  inTransaction(driver) {
+    for (rebuild in diff.partitionRebuilds) {
+      when (rebuild) {
+        PartitionedTableRebuild.Message -> rebuildLegacyMessageTable(driver, instanceId)
+        PartitionedTableRebuild.Conversation -> rebuildLegacyConversationTable(driver, instanceId)
+        PartitionedTableRebuild.Attachment -> rebuildLegacyAttachmentTable(driver, instanceId)
+      }
+    }
+    for (table in diff.createTables) {
+      val sql = MessageDatabaseExpectedSchema.tableCreateSql[table]
+        ?: error("Missing CREATE SQL for $table")
+      driver.execute(identifier = null, sql = sql, parameters = 0)
+    }
+    for (add in diff.addColumns) {
+      if (!tableExists(driver, add.table)) continue
+      if (columnExists(driver, add.table, add.column)) continue
+      driver.execute(
+        identifier = null,
+        sql = "ALTER TABLE ${add.table} ADD COLUMN ${add.column} ${add.definition}",
+        parameters = 0,
+      )
+    }
+    for (indexName in diff.dropIndexes) {
+      driver.execute(identifier = null, sql = "DROP INDEX IF EXISTS $indexName", parameters = 0)
+    }
+    for ((_, createSql) in diff.ensureIndexes) {
+      driver.execute(identifier = null, sql = createSql, parameters = 0)
+    }
+  }
+}
+
+private fun applyExpectedSchema(driver: SqlDriver) {
+  for (table in MessageDatabaseExpectedSchema.managedTables) {
+    val sql = MessageDatabaseExpectedSchema.tableCreateSql[table] ?: continue
+    driver.execute(identifier = null, sql = sql, parameters = 0)
+  }
+  for ((_, createSql) in MessageDatabaseExpectedSchema.requiredIndexes) {
+    driver.execute(identifier = null, sql = createSql, parameters = 0)
+  }
+}
+
+private fun normalizeLegacyConversationIds(driver: SqlDriver) {
+  if (!tableExists(driver, "message")) return
+  runCatching {
+    driver.execute(
+      identifier = null,
+      sql = "UPDATE message SET conversationId = '-1' WHERE conversationId = 'public'",
+      parameters = 0,
+    )
+  }
+  if (!tableExists(driver, "conversation")) return
+  runCatching {
+    driver.execute(
+      identifier = null,
+      sql = "UPDATE conversation SET id = '-1' WHERE id = 'public'",
+      parameters = 0,
+    )
+  }
+}
+
+private fun migrationInstanceId(): String {
+  val known = runBlocking { Settings.lastKnownServerInstanceId.trim() }
+  if (known.isNotEmpty() && isValidInstanceUuid(known)) return known
+  return UNBOUND_MIGRATION_INSTANCE_ID
+}
+
+private fun rebuildLegacyMessageTable(driver: SqlDriver, instanceId: String) {
+  driver.execute(identifier = null, sql = "DROP INDEX IF EXISTS message_conversation_index", parameters = 0)
+  driver.execute(
+    identifier = null,
+    sql = """
+    CREATE TABLE message__migrate (
+        instanceId TEXT NOT NULL,
+        id INTEGER NOT NULL,
+        conversationId TEXT NOT NULL,
+        userId INTEGER NOT NULL,
+        content TEXT NOT NULL,
+        timestamp TEXT NOT NULL,
+        isRead INTEGER NOT NULL,
+        isEdited INTEGER NOT NULL,
+        replyToId INTEGER,
+        clientMessageId TEXT,
+        deletedFlag INTEGER NOT NULL DEFAULT 0,
+        sendStatus TEXT,
+        PRIMARY KEY (instanceId, conversationId, id)
+    )
+    """.trimIndent(),
+    parameters = 0,
+  )
+  driver.execute(
+    identifier = null,
+    sql = """
+    INSERT INTO message__migrate(
+        instanceId, id, conversationId, userId, content, timestamp,
+        isRead, isEdited, replyToId, clientMessageId, deletedFlag, sendStatus
+    )
+    SELECT
+        ?, id,
+        CASE WHEN conversationId = 'public' THEN '-1' ELSE conversationId END,
+        userId, content, timestamp, isRead, isEdited, replyToId, clientMessageId, deletedFlag,
+        CASE WHEN id < 0 THEN 'pending' ELSE 'sent' END
+    FROM message
+    """.trimIndent(),
+    parameters = 1,
+    binders = { bindString(0, instanceId) },
+  )
+  driver.execute(identifier = null, sql = "DROP TABLE message", parameters = 0)
+  driver.execute(identifier = null, sql = "ALTER TABLE message__migrate RENAME TO message", parameters = 0)
+  driver.execute(
+    identifier = null,
+    sql = MessageDatabaseExpectedSchema.requiredIndexes.getValue("message_instance_conversation_index"),
+    parameters = 0,
+  )
+}
+
+private fun rebuildLegacyConversationTable(driver: SqlDriver, instanceId: String) {
+  driver.execute(
+    identifier = null,
+    sql = """
+    CREATE TABLE conversation__migrate (
+        instanceId TEXT NOT NULL,
+        id TEXT NOT NULL,
+        type TEXT NOT NULL,
+        otherUserId INTEGER,
+        displayName TEXT,
+        lastMessageId INTEGER,
+        lastMessagePreview TEXT,
+        unreadCount INTEGER NOT NULL DEFAULT 0,
+        updatedAt TEXT,
+        PRIMARY KEY (instanceId, id)
+    )
+    """.trimIndent(),
+    parameters = 0,
+  )
+  driver.execute(
+    identifier = null,
+    sql = """
+    INSERT INTO conversation__migrate(
+        instanceId, id, type, otherUserId, displayName,
+        lastMessageId, lastMessagePreview, unreadCount, updatedAt
+    )
+    SELECT
+        ?,
+        CASE WHEN id = 'public' THEN '-1' ELSE id END,
+        type, otherUserId, displayName,
+        lastMessageId, lastMessagePreview, unreadCount, updatedAt
+    FROM conversation
+    """.trimIndent(),
+    parameters = 1,
+    binders = { bindString(0, instanceId) },
+  )
+  driver.execute(identifier = null, sql = "DROP TABLE conversation", parameters = 0)
+  driver.execute(identifier = null, sql = "ALTER TABLE conversation__migrate RENAME TO conversation", parameters = 0)
+}
+
+private fun rebuildLegacyAttachmentTable(driver: SqlDriver, instanceId: String) {
+  driver.execute(
+    identifier = null,
+    sql = """
+    CREATE TABLE attachment__migrate (
+        instanceId TEXT NOT NULL,
+        id INTEGER NOT NULL,
+        messageId INTEGER NOT NULL,
+        conversationId TEXT NOT NULL,
+        remotePath TEXT,
+        localPath TEXT,
+        status TEXT NOT NULL,
+        blurhash TEXT,
+        aspectRatio REAL,
+        size INTEGER,
+        bytesTransferred INTEGER NOT NULL DEFAULT 0,
+        clientMessageId TEXT,
+        PRIMARY KEY (instanceId, id, messageId, conversationId)
+    )
+    """.trimIndent(),
+    parameters = 0,
+  )
+  driver.execute(
+    identifier = null,
+    sql = """
+    INSERT INTO attachment__migrate(
+        instanceId, id, messageId, conversationId, remotePath, localPath,
+        status, blurhash, aspectRatio, size, bytesTransferred, clientMessageId
+    )
+    SELECT
+        ?, id, messageId,
+        CASE WHEN conversationId = 'public' THEN '-1' ELSE conversationId END,
+        remotePath, localPath, status, blurhash, aspectRatio, size, 0, NULL
+    FROM attachment
+    """.trimIndent(),
+    parameters = 1,
+    binders = { bindString(0, instanceId) },
+  )
+  driver.execute(identifier = null, sql = "DROP TABLE attachment", parameters = 0)
+  driver.execute(identifier = null, sql = "ALTER TABLE attachment__migrate RENAME TO attachment", parameters = 0)
+}
+
+private fun recreateMessageDatabaseSchema(driver: SqlDriver) {
+  val drops = listOf(
+    "DROP INDEX IF EXISTS message_instance_conversation_index",
+    "DROP INDEX IF EXISTS message_conversation_index",
+    "DROP TABLE IF EXISTS message",
+    "DROP TABLE IF EXISTS message__migrate",
+    "DROP TABLE IF EXISTS attachment",
+    "DROP TABLE IF EXISTS attachment__migrate",
+    "DROP TABLE IF EXISTS outbox",
+    "DROP TABLE IF EXISTS profile_cache",
+    "DROP TABLE IF EXISTS conversation",
+    "DROP TABLE IF EXISTS conversation__migrate",
+    "DROP TABLE IF EXISTS server_binding",
+    "DROP TABLE IF EXISTS instance_registry",
+  )
+  for (sql in drops) {
+    driver.execute(identifier = null, sql = sql, parameters = 0)
+  }
+  applyExpectedSchema(driver)
+}
+
+private fun inTransaction(driver: SqlDriver, block: () -> Unit) {
+  driver.execute(identifier = null, sql = "BEGIN IMMEDIATE", parameters = 0)
+  try {
+    block()
+    driver.execute(identifier = null, sql = "COMMIT", parameters = 0)
+  } catch (e: Exception) {
+    runCatching { driver.execute(identifier = null, sql = "ROLLBACK", parameters = 0) }
+    throw e
+  }
+}
+
+private fun listTables(driver: SqlDriver): Set<String> {
+  val names = mutableSetOf<String>()
+  driver.executeQuery(
+    identifier = null,
+    sql = "SELECT name FROM sqlite_master WHERE type='table' AND name NOT LIKE 'sqlite_%'",
+    mapper = { cursor ->
+      while (cursor.next().value) {
+        names.add(cursor.getString(0)!!)
+      }
+      QueryResult.Value(Unit)
+    },
+    parameters = 0,
+  )
+  return names
+}
+
+private fun columnNames(driver: SqlDriver, table: String): Set<String> {
+  val names = mutableSetOf<String>()
+  driver.executeQuery(
+    identifier = null,
+    sql = "PRAGMA table_info($table)",
+    mapper = { cursor ->
+      while (cursor.next().value) {
+        names.add(cursor.getString(1)!!)
+      }
+      QueryResult.Value(Unit)
+    },
+    parameters = 0,
+  )
+  return names
+}
+
+private fun tableExists(driver: SqlDriver, table: String): Boolean =
+  listTables(driver).contains(table)
+
+private fun columnExists(driver: SqlDriver, table: String, column: String): Boolean =
+  columnNames(driver, table).contains(column)
+
+private fun indexExists(driver: SqlDriver, indexName: String): Boolean =
+  driver.executeQuery(
+    identifier = null,
+    sql = "SELECT 1 FROM sqlite_master WHERE type='index' AND name=? LIMIT 1",
+    mapper = { cursor -> QueryResult.Value(cursor.next().value) },
+    parameters = 1,
+    binders = { bindString(0, indexName) },
+  ).value

app/shared/src/commonMain/kotlin/ru/fromchat/api/db/MessageRepository.kt

@@ -0,0 +1,69 @@
+package ru.fromchat.api.db
+
+import kotlinx.coroutines.flow.Flow
+import ru.fromchat.api.Message
+import ru.fromchat.core.cache.CacheContext
+
+/**
+ * Instance-scoped message access for UI and send pipeline.
+ */
+object MessageRepository {
+    private fun activeInstance(): String = CacheContext.requireActiveInstanceId()
+
+    fun observeMessages(conversationId: String): Flow<List<Message>> =
+        MessageCacheStore.observeMessages(activeInstance(), conversationId)
+
+    fun observePublicMessages(): Flow<List<Message>> =
+        observeMessages(conversationIdForGroup(GENERAL_PUBLIC_GROUP_ID))
+
+    fun observeDmMessages(otherUserId: Int): Flow<List<Message>> =
+        observeMessages(conversationIdForDm(otherUserId))
+
+    suspend fun loadPublicMessages(): List<Message> = MessageCacheStore.loadPublicMessages()
+
+    suspend fun loadRecentPublicMessages(limit: Long): List<Message> =
+        MessageCacheStore.loadRecentPublicMessages(limit)
+
+    suspend fun replacePublicMessages(messages: List<Message>) =
+        MessageCacheStore.replacePublicMessages(messages)
+
+    suspend fun upsertPublicMessage(message: Message) = MessageCacheStore.upsertPublicMessage(message)
+
+    suspend fun confirmPublicMessage(clientMessageId: String, confirmed: Message) =
+        MessageCacheStore.confirmPublicMessage(clientMessageId, confirmed)
+
+    suspend fun deletePublicMessageByClientMessageId(clientMessageId: String) =
+        MessageCacheStore.deletePublicMessageByClientMessageId(clientMessageId)
+
+    suspend fun markMessageDeleted(conversationId: String, messageId: Int) =
+        MessageCacheStore.markMessageDeleted(conversationId, messageId)
+
+    suspend fun markPublicMessageDeleted(messageId: Int) =
+        markMessageDeleted(conversationIdForGroup(GENERAL_PUBLIC_GROUP_ID), messageId)
+
+    suspend fun loadDmMessages(otherUserId: Int): List<Message> =
+        MessageCacheStore.loadDmMessages(otherUserId)
+
+    suspend fun replaceDmMessages(otherUserId: Int, messages: List<Message>) =
+        MessageCacheStore.replaceDmMessages(otherUserId, messages)
+
+    suspend fun upsertDmMessage(otherUserId: Int, message: Message) =
+        MessageCacheStore.upsertDmMessage(otherUserId, message)
+
+    suspend fun confirmDmMessage(otherUserId: Int, clientMessageId: String, confirmed: Message) =
+        MessageCacheStore.confirmDmMessage(otherUserId, clientMessageId, confirmed)
+
+    suspend fun deleteDmMessageByClientMessageId(otherUserId: Int, clientMessageId: String) =
+        MessageCacheStore.deleteDmMessageByClientMessageId(otherUserId, clientMessageId)
+
+    suspend fun deleteDmMessageById(otherUserId: Int, messageId: Int) =
+        MessageCacheStore.deleteDmMessageById(otherUserId, messageId)
+
+    suspend fun replaceDmConversations(conversations: List<ru.fromchat.api.DmConversation>) =
+        MessageCacheStore.replaceDmConversations(conversations)
+
+    suspend fun loadCachedDmConversations(): List<CachedConversation> =
+        MessageCacheStore.loadCachedDmConversations()
+
+    suspend fun clearAllCache() = MessageCacheStore.clearAll()
+}

app/shared/src/commonMain/kotlin/ru/fromchat/api/db/ProfileCacheStore.kt

@@ -0,0 +1,61 @@
+package ru.fromchat.api.db
+
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import kotlinx.serialization.json.Json
+import ru.fromchat.api.UserProfile
+
+object ProfileCacheStore {
+    private val json = Json {
+        ignoreUnknownKeys = true
+        isLenient = true
+        encodeDefaults = true
+    }
+
+    suspend fun get(instanceId: String, userId: Int): UserProfile? = withContext(Dispatchers.Default) {
+        val id = instanceId.trim()
+        if (id.isEmpty()) return@withContext null
+        val raw = MessageDatabaseProvider.database.messageDatabaseQueries
+            .selectProfileCache(id, userId.toLong())
+            .executeAsOneOrNull() ?: return@withContext null
+        runCatching { json.decodeFromString(UserProfile.serializer(), raw) }.getOrNull()
+    }
+
+    suspend fun put(instanceId: String, profile: UserProfile) {
+        val id = instanceId.trim()
+        if (id.isEmpty()) return
+        withContext(Dispatchers.Default) {
+            MessageDatabaseProvider.database.messageDatabaseQueries.upsertProfileCache(
+                instanceId = id,
+                userId = profile.id.toLong(),
+                json = json.encodeToString(UserProfile.serializer(), profile),
+            )
+        }
+    }
+
+    suspend fun remove(instanceId: String, userId: Int) {
+        val id = instanceId.trim()
+        if (id.isEmpty()) return
+        withContext(Dispatchers.Default) {
+            MessageDatabaseProvider.database.messageDatabaseQueries.deleteProfileCache(
+                instanceId = id,
+                userId = userId.toLong(),
+            )
+        }
+    }
+
+    suspend fun loadAllForInstance(instanceId: String): Map<Int, UserProfile> =
+        withContext(Dispatchers.Default) {
+            val id = instanceId.trim()
+            if (id.isEmpty()) return@withContext emptyMap()
+            MessageDatabaseProvider.database.messageDatabaseQueries
+                .selectAllProfilesForInstance(id)
+                .executeAsList()
+                .mapNotNull { row ->
+                    runCatching {
+                        json.decodeFromString(UserProfile.serializer(), row.json) to row.userId.toInt()
+                    }.getOrNull()
+                }
+                .associate { (profile, uid) -> uid to profile }
+        }
+}

app/shared/src/commonMain/kotlin/ru/fromchat/api/outbox/DmAttachmentOutboxHandler.kt

@@ -0,0 +1,400 @@
+package ru.fromchat.api.outbox
+
+import com.pr0gramm3r101.utils.crypto.Base64
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.encodeToString
+import kotlinx.serialization.json.Json
+import ru.fromchat.api.ApiClient
+import ru.fromchat.api.AttachmentUploadNotifier
+import ru.fromchat.api.AttachmentUploadProgress
+import ru.fromchat.api.DmUploadCompleteResponse
+import ru.fromchat.api.SendDmFile
+import ru.fromchat.api.db.MessageCacheStore
+import ru.fromchat.api.db.MessageDatabaseProvider
+import ru.fromchat.api.db.conversationIdForDm
+import ru.fromchat.core.cache.OutboundFileUnavailableException
+import ru.fromchat.core.cache.clearUploadSecretsOnly
+import ru.fromchat.api.optimisticMessageIdForClientMessageId
+import ru.fromchat.core.cache.isOutboundFileUnavailable
+import ru.fromchat.ui.chat.AttachmentMediaLog
+import ru.fromchat.ui.chat.clearOutboundImageCaches
+import ru.fromchat.core.cache.loadEncryptedUploadBlob
+import ru.fromchat.core.cache.loadUploadTransportCipherJson
+import ru.fromchat.core.cache.readOutboundFileBytes
+import ru.fromchat.core.cache.saveEncryptedUploadBlob
+import ru.fromchat.core.cache.saveUploadTransportCipherJson
+import ru.fromchat.core.cache.stageOutboundFileForUpload
+import ru.fromchat.crypto.transport.TransportCiphertext
+import ru.fromchat.crypto.transport.TransportCrypto
+import ru.fromchat.db.Outbox
+
+private const val INLINE_UPLOAD_THRESHOLD_BYTES = 512 * 1024
+private const val DEFAULT_CHUNK_SIZE = 262_144
+
+@Serializable
+private data class StoredTransportCipher(
+    val clientPublicKeyB64: String,
+    val nonceB64: String,
+    val ciphertextB64: String,
+)
+
+object DmAttachmentOutboxHandler {
+    private val json = Json { ignoreUnknownKeys = true; encodeDefaults = true }
+
+    private fun outboxRowExists(instanceId: String, clientMessageId: String): Boolean =
+        MessageDatabaseProvider.database.messageDatabaseQueries
+            .selectOutboxItem(instanceId, clientMessageId)
+            .executeAsOneOrNull() != null
+
+    private fun ensureStillQueued(instanceId: String, clientMessageId: String) {
+        if (!outboxRowExists(instanceId, clientMessageId)) {
+            AttachmentMediaLog.upload("cancelled_in_flight", "job" to clientMessageId)
+            throw kotlinx.coroutines.CancellationException("Upload cancelled")
+        }
+    }
+
+    suspend fun process(row: Outbox): Boolean {
+        if (row.kind != OutgoingMessageCoordinator.KIND_SEND_DM_ATTACHMENT) return false
+        val instanceId = row.instanceId
+        val payload = json.decodeFromString<DmAttachmentOutboxPayload>(row.payloadJson)
+        val clientMessageId = payload.clientMessageId.trim()
+        if (clientMessageId.isEmpty() || payload.recipientId <= 0) return true
+        if (!outboxRowExists(instanceId, clientMessageId)) return true
+
+        val conversationId = row.conversationId.ifBlank {
+            conversationIdForDm(payload.recipientId)
+        }
+        if (MessageCacheStore.hasSentMessageWithClientId(conversationId, clientMessageId)) {
+            withContext(Dispatchers.Default) {
+                MessageDatabaseProvider.database.messageDatabaseQueries.deleteOutboxItem(
+                    instanceId,
+                    clientMessageId,
+                )
+                MessageDatabaseProvider.database.messageDatabaseQueries.deletePendingMessageByClientMessageId(
+                    instanceId,
+                    conversationId,
+                    clientMessageId,
+                )
+            }
+            clearPrepared(instanceId, clientMessageId)
+            clearUploadSecretsOnly(instanceId, clientMessageId)
+            return true
+        }
+
+        val serverUploadId = arrayOf(payload.uploadId.trim())
+        return runCatching {
+            ensureStillQueued(instanceId, clientMessageId)
+            AttachmentUploadNotifier.emit(
+                AttachmentUploadProgress.Pending(clientMessageId, payload.filename),
+                messageLabel = payload.plaintext,
+            )
+            val stagedPayload = ensureStagedPayload(instanceId, row, payload)
+            ensureStillQueued(instanceId, clientMessageId)
+            val restoredPercent = uploadPercent(row.bytesUploaded, stagedPayload)
+            if (restoredPercent > 0) {
+                emitProgress(clientMessageId, restoredPercent, stagedPayload.filename, stagedPayload.plaintext)
+            } else {
+                emitProgress(clientMessageId, 0, stagedPayload.filename, stagedPayload.plaintext)
+            }
+
+            val prepared = loadPrepared(instanceId, clientMessageId)
+            val encryptedBlob: ByteArray
+            val msgCipher: TransportCiphertext
+            var activePayload = stagedPayload
+
+            if (prepared != null) {
+                encryptedBlob = prepared.first
+                msgCipher = prepared.second
+                if (activePayload.encryptedFileSizeBytes <= 0L) {
+                    activePayload = activePayload.copy(encryptedFileSizeBytes = encryptedBlob.size.toLong())
+                }
+            } else {
+                ensureStillQueued(instanceId, clientMessageId)
+                val bytes = readOutboundFileBytes(stagedPayload.fileUri)
+                OutgoingMessageCoordinator.abortDmServerUploadIfNeeded(stagedPayload.uploadId)
+                serverUploadId[0] = ""
+                activePayload = stagedPayload.copy(uploadId = "", encryptedFileSizeBytes = 0L)
+                persistPayloadProgress(instanceId, row, activePayload, bytesUploaded = 0L)
+                ensureStillQueued(instanceId, clientMessageId)
+                val transportKey = ApiClient.getTransportPublicKey()
+                val (freshCipher, ephemeralSecret) = TransportCrypto.encryptWithTransportKeyWithEphemeralSecret(
+                    plaintext = stagedPayload.plaintext,
+                    transportPublicKeyB64 = transportKey.publicKeyB64,
+                )
+                try {
+                    val blob = TransportCrypto.encryptFileForTransport(
+                        fileBytes = bytes,
+                        transportPublicKeyB64 = transportKey.publicKeyB64,
+                        ephemeralSecretKey = ephemeralSecret,
+                    )
+                    encryptedBlob = blob
+                    msgCipher = freshCipher
+                    savePrepared(instanceId, clientMessageId, encryptedBlob, msgCipher)
+                    activePayload = activePayload.copy(encryptedFileSizeBytes = encryptedBlob.size.toLong())
+                    persistPayloadProgress(instanceId, row, activePayload, bytesUploaded = 0L)
+                } finally {
+                    ephemeralSecret.fill(0)
+                }
+            }
+
+            ensureStillQueued(instanceId, clientMessageId)
+            if (encryptedBlob.size <= INLINE_UPLOAD_THRESHOLD_BYTES) {
+                sendInline(activePayload, encryptedBlob, msgCipher)
+            } else {
+                sendResumable(
+                    instanceId = instanceId,
+                    row = row,
+                    payload = activePayload,
+                    encryptedBlob = encryptedBlob,
+                    msgCipher = msgCipher,
+                    serverUploadId = serverUploadId,
+                )
+            }
+            ensureStillQueued(instanceId, clientMessageId)
+
+            clearPrepared(instanceId, clientMessageId)
+            withContext(Dispatchers.Default) {
+                MessageDatabaseProvider.database.messageDatabaseQueries.upsertOutbox(
+                    instanceId = instanceId,
+                    clientMessageId = clientMessageId,
+                    conversationId = row.conversationId,
+                    kind = OutgoingMessageCoordinator.KIND_SEND_DM_ATTACHMENT_AWAITING_ACK,
+                    payloadJson = row.payloadJson,
+                    retryCount = row.retryCount,
+                    nextAttemptAt = null,
+                    bytesUploaded = row.bytesUploaded,
+                )
+            }
+            AttachmentUploadNotifier.emit(
+                AttachmentUploadProgress.Success(clientMessageId),
+                messageLabel = payload.plaintext,
+            )
+            true
+        }.getOrElse { error ->
+            if (error is kotlinx.coroutines.CancellationException) {
+                OutgoingMessageCoordinator.abortDmServerUploadIfNeeded(serverUploadId[0])
+                return true
+            }
+            if (error.isOutboundFileUnavailable()) {
+                AttachmentUploadNotifier.emit(
+                    AttachmentUploadProgress.Failed(
+                        jobId = clientMessageId,
+                        error = error.message ?: "Attachment unavailable",
+                    ),
+                    messageLabel = payload.plaintext,
+                )
+                runCatching {
+                    clearOutboundImageCaches(
+                        clientMessageId,
+                        optimisticMessageIdForClientMessageId(clientMessageId),
+                    )
+                    OutgoingMessageCoordinator.cancelOutboundMessage(clientMessageId, row.conversationId)
+                }
+                return true
+            }
+            AttachmentUploadNotifier.emit(
+                AttachmentUploadProgress.Failed(
+                    jobId = clientMessageId,
+                    error = error.message ?: "Upload failed",
+                ),
+                messageLabel = payload.plaintext,
+            )
+            false
+        }
+    }
+
+    private suspend fun sendInline(
+        payload: DmAttachmentOutboxPayload,
+        encryptedBlob: ByteArray,
+        msgCipher: TransportCiphertext,
+    ) {
+        val file = SendDmFile(
+            encryptedFileDataB64 = Base64.encode(encryptedBlob),
+            filename = payload.filename,
+            fileSize = encryptedBlob.size.toLong(),
+        )
+        ApiClient.sendDm(
+            recipientId = payload.recipientId,
+            plaintext = payload.plaintext,
+            clientMessageId = payload.clientMessageId,
+            replyToId = payload.replyToId,
+            transportFiles = listOf(file),
+            preparedTransport = msgCipher,
+        )
+    }
+
+    private suspend fun sendResumable(
+        instanceId: String,
+        row: Outbox,
+        payload: DmAttachmentOutboxPayload,
+        encryptedBlob: ByteArray,
+        msgCipher: TransportCiphertext,
+        serverUploadId: Array<String>,
+    ) {
+        var uploadId = payload.uploadId.trim().ifBlank { serverUploadId[0] }
+        try {
+            if (uploadId.isEmpty()) {
+                val init = ApiClient.initDmUpload(
+                    filename = payload.filename,
+                    totalSize = encryptedBlob.size.toLong(),
+                    recipientId = payload.recipientId,
+                    chunkSize = DEFAULT_CHUNK_SIZE,
+                )
+                uploadId = init.uploadId
+                serverUploadId[0] = uploadId
+                persistPayloadProgress(instanceId, row, payload.copy(uploadId = uploadId), row.bytesUploaded)
+            } else {
+                serverUploadId[0] = uploadId
+            }
+
+            var offset = row.bytesUploaded.toInt().coerceAtLeast(0)
+            val serverOffset = ApiClient.getDmUploadStatus(uploadId).offset.toInt().coerceAtLeast(0)
+            offset = maxOf(offset, serverOffset)
+            while (offset < encryptedBlob.size) {
+                ensureStillQueued(instanceId, payload.clientMessageId)
+                val nextOffset = minOf(offset + DEFAULT_CHUNK_SIZE, encryptedBlob.size)
+                val chunk = encryptedBlob.copyOfRange(offset, nextOffset)
+                ApiClient.uploadDmChunk(
+                    uploadId = uploadId,
+                    offset = offset.toLong(),
+                    dataB64 = Base64.encode(chunk),
+                )
+                offset = nextOffset
+                val percent = ((offset.toDouble() / encryptedBlob.size.toDouble()) * 100.0).toInt()
+                emitProgress(payload.clientMessageId, percent, payload.filename, payload.plaintext)
+                persistPayloadProgress(
+                    instanceId,
+                    row,
+                    payload.copy(uploadId = uploadId),
+                    offset.toLong(),
+                )
+            }
+
+            val completed: DmUploadCompleteResponse = ApiClient.completeDmUpload(uploadId)
+            ApiClient.sendDm(
+                recipientId = payload.recipientId,
+                plaintext = payload.plaintext,
+                clientMessageId = payload.clientMessageId,
+                replyToId = payload.replyToId,
+                uploadedFileIds = listOf(completed.fileId),
+                preparedTransport = msgCipher,
+            )
+            serverUploadId[0] = ""
+        } catch (e: kotlinx.coroutines.CancellationException) {
+            OutgoingMessageCoordinator.abortDmServerUploadIfNeeded(uploadId)
+            serverUploadId[0] = ""
+            throw e
+        }
+    }
+
+    private suspend fun ensureStagedPayload(
+        instanceId: String,
+        row: Outbox,
+        payload: DmAttachmentOutboxPayload,
+    ): DmAttachmentOutboxPayload {
+        val staged = stageOutboundFileForUpload(instanceId, payload.clientMessageId, payload.fileUri)
+        if (staged.sizeBytes <= 0L) {
+            throw OutboundFileUnavailableException("Attachment file is empty or unavailable")
+        }
+        if (staged.uri == payload.fileUri && staged.sizeBytes == payload.fileSizeBytes) {
+            return payload
+        }
+        val updated = payload.copy(fileUri = staged.uri, fileSizeBytes = staged.sizeBytes)
+        persistPayloadProgress(instanceId, row, updated, row.bytesUploaded)
+        return updated
+    }
+
+    private suspend fun persistPayloadProgress(
+        instanceId: String,
+        row: Outbox,
+        payload: DmAttachmentOutboxPayload,
+        bytesUploaded: Long,
+    ) {
+        if (!outboxRowExists(instanceId, row.clientMessageId)) return
+        withContext(Dispatchers.Default) {
+            if (!outboxRowExists(instanceId, row.clientMessageId)) return@withContext
+            MessageDatabaseProvider.database.messageDatabaseQueries.upsertOutbox(
+                instanceId = instanceId,
+                clientMessageId = row.clientMessageId,
+                conversationId = row.conversationId,
+                kind = row.kind,
+                payloadJson = json.encodeToString(payload),
+                retryCount = row.retryCount,
+                nextAttemptAt = row.nextAttemptAt,
+                bytesUploaded = bytesUploaded,
+            )
+        }
+    }
+
+    private suspend fun loadPrepared(
+        instanceId: String,
+        clientMessageId: String,
+    ): Pair<ByteArray, TransportCiphertext>? {
+        val blob = loadEncryptedUploadBlob(instanceId, clientMessageId) ?: return null
+        val raw = loadUploadTransportCipherJson(instanceId, clientMessageId) ?: return null
+        return runCatching {
+            val stored = json.decodeFromString<StoredTransportCipher>(raw)
+            val cipher = TransportCiphertext(
+                clientPublicKeyB64 = stored.clientPublicKeyB64,
+                nonceB64 = stored.nonceB64,
+                ciphertextB64 = stored.ciphertextB64,
+            )
+            blob to cipher
+        }.getOrNull()
+    }
+
+    private suspend fun savePrepared(
+        instanceId: String,
+        clientMessageId: String,
+        blob: ByteArray,
+        cipher: TransportCiphertext,
+    ) {
+        saveEncryptedUploadBlob(instanceId, clientMessageId, blob)
+        val stored = StoredTransportCipher(
+            clientPublicKeyB64 = cipher.clientPublicKeyB64,
+            nonceB64 = cipher.nonceB64,
+            ciphertextB64 = cipher.ciphertextB64,
+        )
+        saveUploadTransportCipherJson(instanceId, clientMessageId, json.encodeToString(stored))
+    }
+
+    private suspend fun clearPrepared(instanceId: String, clientMessageId: String) {
+        clearUploadSecretsOnly(instanceId, clientMessageId)
+    }
+
+    private fun uploadPercent(bytesUploaded: Long, payload: DmAttachmentOutboxPayload): Int {
+        val total = when {
+            payload.encryptedFileSizeBytes > 0L -> payload.encryptedFileSizeBytes
+            payload.fileSizeBytes > 0L -> payload.fileSizeBytes
+            else -> 0L
+        }
+        if (total <= 0L || bytesUploaded <= 0L) return 0
+        return ((bytesUploaded.toDouble() / total.toDouble()) * 100.0).toInt().coerceIn(0, 99)
+    }
+
+    private fun emitProgress(
+        jobId: String,
+        percent: Int,
+        filename: String? = null,
+        messageLabel: String? = null,
+    ) {
+        AttachmentUploadNotifier.emit(
+            AttachmentUploadProgress.InProgress(
+                jobId = jobId,
+                percent = percent.coerceIn(0, 100),
+                filename = filename,
+            ),
+            messageLabel = messageLabel,
+        )
+    }
+
+    suspend fun hasPendingAttachmentWork(instanceId: String): Boolean =
+        withContext(Dispatchers.Default) {
+            MessageDatabaseProvider.database.messageDatabaseQueries
+                .selectPendingOutboxForInstance(instanceId)
+                .executeAsList()
+                .any { it.kind == OutgoingMessageCoordinator.KIND_SEND_DM_ATTACHMENT }
+        }
+}

app/shared/src/commonMain/kotlin/ru/fromchat/api/outbox/OutboxPayloads.kt

@@ -0,0 +1,35 @@
+package ru.fromchat.api.outbox
+
+import kotlinx.serialization.Serializable
+import ru.fromchat.api.SendDmFile
+
+@Serializable
+data class PublicOutboxPayload(
+    val content: String,
+    val replyToId: Int? = null,
+)
+
+@Serializable
+data class DmOutboxPayload(
+    val recipientId: Int,
+    val plaintext: String,
+    val clientMessageId: String? = null,
+    val replyToId: Int? = null,
+    val transportFiles: List<SendDmFile> = emptyList(),
+    val uploadedFileIds: List<String> = emptyList(),
+)
+
+@Serializable
+data class DmAttachmentOutboxPayload(
+    val recipientId: Int,
+    val plaintext: String,
+    val clientMessageId: String,
+    val replyToId: Int? = null,
+    val fileUri: String,
+    val filename: String,
+    val fileSizeBytes: Long = 0L,
+    val aspectRatio: Float? = null,
+    /** Encrypted blob size; used for upload progress after encryption. */
+    val encryptedFileSizeBytes: Long = 0L,
+    val uploadId: String = "",
+)

app/shared/src/commonMain/kotlin/ru/fromchat/api/outbox/OutboxProcessor.kt

@@ -0,0 +1,8 @@
+package ru.fromchat.api.outbox
+
+/**
+ * Drains pending outbox rows for the active instance (Android: WorkManager; iOS: BG task hook).
+ */
+expect fun scheduleOutboxProcessing(instanceId: String)
+
+expect fun cancelOutboxProcessing(instanceId: String)

app/shared/src/commonMain/kotlin/ru/fromchat/api/outbox/OutgoingMessageCoordinator.kt

@@ -0,0 +1,307 @@
+package ru.fromchat.api.outbox
+
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
+import kotlinx.coroutines.withContext
+import ru.fromchat.api.AttachmentUploadNotifier
+import ru.fromchat.api.AttachmentUploadProgress
+import ru.fromchat.ui.chat.AttachmentMediaLog
+import kotlinx.serialization.encodeToString
+import kotlinx.serialization.json.Json
+import ru.fromchat.api.ApiClient
+import ru.fromchat.api.Message
+import ru.fromchat.api.db.MessageCacheStore
+import ru.fromchat.api.db.MessageDatabaseProvider
+import ru.fromchat.api.db.MessageRepository
+import ru.fromchat.api.db.conversationIdForDm
+import ru.fromchat.api.db.conversationIdForGroup
+import ru.fromchat.api.db.GENERAL_PUBLIC_GROUP_ID
+import ru.fromchat.core.cache.CacheContext
+import ru.fromchat.core.cache.clearUploadArtifacts
+import ru.fromchat.core.cache.clearUploadSecretsOnly
+import ru.fromchat.core.cache.readOutboundFileBytes
+
+/**
+ * Single entry point for enqueueing outbound messages (DB row + outbox + worker).
+ * Panels must not call [ApiClient.sendMessage] / [ApiClient.sendDm] directly.
+ */
+object OutgoingMessageCoordinator {
+    private val json = Json { ignoreUnknownKeys = true; encodeDefaults = true }
+    private val drainMutex = Mutex()
+    private val drainScope = CoroutineScope(SupervisorJob() + Dispatchers.Default)
+
+    private fun kickOutboxDrain(instanceId: String) {
+        val id = instanceId.trim()
+        if (id.isEmpty()) return
+        scheduleOutboxProcessing(id)
+        drainScope.launch { drainOutboxForInstance(id) }
+    }
+
+    suspend fun enqueuePublicMessage(
+        content: String,
+        replyToId: Int?,
+        clientMessageId: String,
+        optimisticMessage: Message,
+    ) {
+        val instanceId = CacheContext.requireActiveInstanceId()
+        val conversationId = conversationIdForGroup(GENERAL_PUBLIC_GROUP_ID)
+        withContext(Dispatchers.Default) {
+            MessageRepository.upsertPublicMessage(optimisticMessage)
+            val payload = json.encodeToString(PublicOutboxPayload(content, replyToId))
+            MessageDatabaseProvider.database.messageDatabaseQueries.upsertOutbox(
+                instanceId = instanceId,
+                clientMessageId = clientMessageId,
+                conversationId = conversationId,
+                kind = KIND_SEND_PUBLIC,
+                payloadJson = payload,
+                retryCount = 0L,
+                nextAttemptAt = null,
+                bytesUploaded = 0L,
+            )
+        }
+        kickOutboxDrain(instanceId)
+    }
+
+    suspend fun enqueueDmMessage(
+        recipientId: Int,
+        plaintext: String,
+        clientMessageId: String,
+        replyToId: Int?,
+        optimisticMessage: Message,
+        transportFiles: List<ru.fromchat.api.SendDmFile> = emptyList(),
+        uploadedFileIds: List<String> = emptyList(),
+    ) {
+        val instanceId = CacheContext.requireActiveInstanceId()
+        val conversationId = conversationIdForDm(recipientId)
+        withContext(Dispatchers.Default) {
+            MessageRepository.upsertDmMessage(recipientId, optimisticMessage)
+            val payload = json.encodeToString(
+                DmOutboxPayload(
+                    recipientId = recipientId,
+                    plaintext = plaintext,
+                    clientMessageId = clientMessageId,
+                    replyToId = replyToId,
+                    transportFiles = transportFiles,
+                    uploadedFileIds = uploadedFileIds,
+                ),
+            )
+            MessageDatabaseProvider.database.messageDatabaseQueries.upsertOutbox(
+                instanceId = instanceId,
+                clientMessageId = clientMessageId,
+                conversationId = conversationId,
+                kind = KIND_SEND_DM,
+                payloadJson = payload,
+                retryCount = 0L,
+                nextAttemptAt = null,
+                bytesUploaded = 0L,
+            )
+        }
+        kickOutboxDrain(instanceId)
+    }
+
+    suspend fun enqueueDmAttachment(
+        recipientId: Int,
+        plaintext: String,
+        clientMessageId: String,
+        replyToId: Int?,
+        fileUri: String,
+        filename: String,
+        optimisticMessage: Message,
+        aspectRatio: Float? = null,
+    ) {
+        val instanceId = CacheContext.requireActiveInstanceId()
+        val conversationId = conversationIdForDm(recipientId)
+        AttachmentUploadNotifier.emit(
+            AttachmentUploadProgress.Pending(clientMessageId, filename),
+            messageLabel = plaintext,
+        )
+        AttachmentUploadNotifier.emit(
+            AttachmentUploadProgress.InProgress(clientMessageId, 1, filename),
+            messageLabel = plaintext,
+        )
+        withContext(Dispatchers.Default) {
+            MessageRepository.upsertDmMessage(recipientId, optimisticMessage)
+            val payload = json.encodeToString(
+                DmAttachmentOutboxPayload(
+                    recipientId = recipientId,
+                    plaintext = plaintext,
+                    clientMessageId = clientMessageId,
+                    replyToId = replyToId,
+                    fileUri = fileUri,
+                    filename = filename,
+                    fileSizeBytes = 0L,
+                    aspectRatio = aspectRatio?.takeIf { it > 0f },
+                ),
+            )
+            MessageDatabaseProvider.database.messageDatabaseQueries.upsertOutbox(
+                instanceId = instanceId,
+                clientMessageId = clientMessageId,
+                conversationId = conversationId,
+                kind = KIND_SEND_DM_ATTACHMENT,
+                payloadJson = payload,
+                retryCount = 0L,
+                nextAttemptAt = null,
+                bytesUploaded = 0L,
+            )
+        }
+        kickOutboxDrain(instanceId)
+    }
+
+    suspend fun clearAttachmentOutboxAfterAck(clientMessageId: String) {
+        val cid = clientMessageId.trim()
+        if (cid.isEmpty()) return
+        val instanceId = CacheContext.requireActiveInstanceId()
+        withContext(Dispatchers.Default) {
+            MessageDatabaseProvider.database.messageDatabaseQueries.deleteOutboxItem(instanceId, cid)
+        }
+    }
+
+    /** Best-effort DELETE of an in-progress resumable upload session on the server. */
+    suspend fun abortDmServerUploadIfNeeded(uploadId: String) {
+        val id = uploadId.trim()
+        if (id.isEmpty()) return
+        runCatching { ApiClient.abortDmUpload(id) }
+            .onSuccess {
+                AttachmentMediaLog.upload("server_abort_ok", "uploadId" to id)
+            }
+            .onFailure { error ->
+                AttachmentMediaLog.upload(
+                    "server_abort_failed",
+                    "uploadId" to id,
+                    "error" to (error.message ?: "unknown"),
+                )
+            }
+    }
+
+    /** Drops a queued outbound row, local message, and any upload artifacts. */
+    suspend fun cancelOutboundMessage(clientMessageId: String, conversationId: String) {
+        val cid = clientMessageId.trim()
+        if (cid.isEmpty()) return
+        val instanceId = CacheContext.requireActiveInstanceId()
+        AttachmentMediaLog.upload("cancel_requested", "job" to cid, "conv" to conversationId)
+        withContext(Dispatchers.Default) {
+            val row = MessageDatabaseProvider.database.messageDatabaseQueries
+                .selectOutboxItem(instanceId, cid)
+                .executeAsOneOrNull()
+            if (row?.kind == KIND_SEND_DM_ATTACHMENT) {
+                runCatching {
+                    val payload = json.decodeFromString<DmAttachmentOutboxPayload>(row.payloadJson)
+                    abortDmServerUploadIfNeeded(payload.uploadId)
+                }
+            }
+            MessageDatabaseProvider.database.messageDatabaseQueries.deleteOutboxItem(instanceId, cid)
+            MessageCacheStore.deleteMessageByClientMessageId(conversationId, cid)
+            clearUploadArtifacts(instanceId, cid)
+        }
+        AttachmentUploadNotifier.emit(
+            AttachmentUploadProgress.Failed(cid, "Cancelled"),
+        )
+        kickOutboxDrain(instanceId)
+    }
+
+    /** Drains pending outbox rows for the active instance (shared by workers and iOS). */
+    suspend fun drainActiveInstanceOutbox(): Boolean =
+        drainOutboxForInstance(CacheContext.activeInstanceId.value.trim())
+
+    /** Drains pending outbox rows for [instanceId]. Returns false if any attachment upload failed. */
+    suspend fun drainOutboxForInstance(instanceId: String): Boolean {
+        val id = instanceId.trim()
+        if (id.isEmpty()) return true
+        return drainMutex.withLock {
+            pruneStaleAttachmentOutbox(id)
+            val rows = withContext(Dispatchers.Default) {
+                MessageDatabaseProvider.database.messageDatabaseQueries
+                    .selectPendingOutboxForInstance(id)
+                    .executeAsList()
+            }
+            var allOk = true
+            for (row in rows) {
+                when (row.kind) {
+                    KIND_SEND_PUBLIC -> {
+                        runCatching {
+                            val payload = json.decodeFromString<PublicOutboxPayload>(row.payloadJson)
+                            ApiClient.sendMessageViaHttp(payload.content, payload.replyToId)
+                            withContext(Dispatchers.Default) {
+                                MessageDatabaseProvider.database.messageDatabaseQueries
+                                    .deleteOutboxItem(id, row.clientMessageId)
+                            }
+                        }
+                    }
+                    KIND_SEND_DM -> {
+                        runCatching {
+                            val payload = json.decodeFromString<DmOutboxPayload>(row.payloadJson)
+                            ApiClient.sendDm(
+                                recipientId = payload.recipientId,
+                                plaintext = payload.plaintext,
+                                clientMessageId = payload.clientMessageId,
+                                replyToId = payload.replyToId,
+                                transportFiles = payload.transportFiles,
+                                uploadedFileIds = payload.uploadedFileIds,
+                            )
+                            withContext(Dispatchers.Default) {
+                                MessageDatabaseProvider.database.messageDatabaseQueries
+                                    .deleteOutboxItem(id, row.clientMessageId)
+                            }
+                        }
+                    }
+                    KIND_SEND_DM_ATTACHMENT -> {
+                        if (!DmAttachmentOutboxHandler.process(row)) {
+                            allOk = false
+                            drainScope.launch {
+                                delay(3_000)
+                                drainOutboxForInstance(id)
+                            }
+                        }
+                    }
+                    KIND_SEND_DM_ATTACHMENT_AWAITING_ACK -> Unit
+                }
+            }
+            allOk
+        }
+    }
+
+    const val KIND_SEND_PUBLIC = "send_public"
+    const val KIND_SEND_DM = "send_dm"
+    const val KIND_SEND_DM_ATTACHMENT = "send_dm_attachment"
+    /** Upload+send finished; row kept until DM ack so UI can still resolve local preview from outbox. */
+    const val KIND_SEND_DM_ATTACHMENT_AWAITING_ACK = "send_dm_attachment_awaiting_ack"
+
+    suspend fun pruneStaleAttachmentOutboxForInstance(instanceId: String) {
+        val id = instanceId.trim()
+        if (id.isEmpty()) return
+        pruneStaleAttachmentOutbox(id)
+    }
+
+    private suspend fun pruneStaleAttachmentOutbox(instanceId: String) {
+        withContext(Dispatchers.Default) {
+            val db = MessageDatabaseProvider.database.messageDatabaseQueries
+            val rows = db.selectPendingOutboxForInstance(instanceId).executeAsList()
+            for (row in rows) {
+                when (row.kind) {
+                    KIND_SEND_DM_ATTACHMENT,
+                    KIND_SEND_DM_ATTACHMENT_AWAITING_ACK -> {
+                        if (!MessageCacheStore.hasSentMessageWithClientId(
+                                row.conversationId,
+                                row.clientMessageId,
+                            )
+                        ) {
+                            continue
+                        }
+                        db.deleteOutboxItem(instanceId, row.clientMessageId)
+                        db.deletePendingMessageByClientMessageId(
+                            instanceId,
+                            row.conversationId,
+                            row.clientMessageId,
+                        )
+                        clearUploadSecretsOnly(instanceId, row.clientMessageId)
+                    }
+                }
+            }
+        }
+    }
+}

app/shared/src/commonMain/kotlin/ru/fromchat/core/ServerConfigKeys.kt

@@ -0,0 +1,6 @@
+package ru.fromchat.core
+
+fun ServerConfigData.configKey(): String {
+    val scheme = if (httpsEnabled) "1" else "0"
+    return "${serverIp.trim().lowercase()}|$apiPort|$scheme"
+}

app/shared/src/commonMain/kotlin/ru/fromchat/core/Settings.kt

@@ -6,6 +6,7 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.IO
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.runBlocking
+import kotlinx.coroutines.withContext
 import kotlinx.serialization.builtins.ListSerializer
 import kotlinx.serialization.json.Json
 import ru.fromchat.api.DeviceSessionInfo
@@ -106,45 +107,57 @@ object Settings {
         throw IllegalStateException("Server config not initialized")
 
     var serverConfig: ServerConfigData
-        get() = runBlocking {
-            migrateLegacyServerUrlIfNeeded()
-            if (!settings.contains(SERVER_IP_KEY)) {
-                settings.putString(SERVER_IP_KEY, "fromchat.ru")
-                settings.putInt(API_PORT_KEY, 443)
-                settings.putInt(CALLS_PORT_KEY, DEFAULT_CALLS_PORT)
-                if (!settings.contains(HTTPS_ENABLED_KEY)) {
-                    settings.putBoolean(HTTPS_ENABLED_KEY, true)
-                }
-            }
-            val ip = settings.getString(SERVER_IP_KEY)
-            if (ip.isBlank()) {
-                serverConfigNotInitialized()
-            }
-            val apiPort = settings.getInt(API_PORT_KEY, 443).coerceIn(1, 65535)
-            val rawCalls = settings.getInt(CALLS_PORT_KEY, -1)
-            val callsPort = if (rawCalls in 1..65535) rawCalls else DEFAULT_CALLS_PORT
-            val https = settings.getBoolean(HTTPS_ENABLED_KEY, true)
-            val callsEnabled =
-                if (settings.contains(CALLS_ENABLED_KEY)) {
-                    settings.getBoolean(CALLS_ENABLED_KEY, true)
-                } else {
-                    true
-                }
-            ServerConfigData(
-                serverIp = ip,
-                apiPort = apiPort,
-                callsPort = callsPort,
-                httpsEnabled = https,
-                callsEnabled = callsEnabled,
-            )
+        get() = runBlocking { readServerConfig() }
+        set(value) {
+            runIO { writeServerConfig(value) }
         }
-        set(value) = runIO {
-            settings.putString(SERVER_IP_KEY, value.serverIp.trim())
-            settings.putInt(API_PORT_KEY, value.apiPort.coerceIn(1, 65535))
-            settings.putInt(CALLS_PORT_KEY, value.callsPort.coerceIn(1, 65535))
-            settings.putBoolean(HTTPS_ENABLED_KEY, value.httpsEnabled)
-            settings.putBoolean(CALLS_ENABLED_KEY, value.callsEnabled)
+
+    suspend fun setServerConfig(value: ServerConfigData) {
+        withContext(Dispatchers.IO) {
+            writeServerConfig(value)
         }
+    }
+
+    suspend fun readServerConfig(): ServerConfigData {
+        migrateLegacyServerUrlIfNeeded()
+        if (!settings.contains(SERVER_IP_KEY)) {
+            settings.putString(SERVER_IP_KEY, "fromchat.ru")
+            settings.putInt(API_PORT_KEY, 443)
+            settings.putInt(CALLS_PORT_KEY, DEFAULT_CALLS_PORT)
+            if (!settings.contains(HTTPS_ENABLED_KEY)) {
+                settings.putBoolean(HTTPS_ENABLED_KEY, true)
+            }
+        }
+        val ip = settings.getString(SERVER_IP_KEY)
+        if (ip.isBlank()) {
+            serverConfigNotInitialized()
+        }
+        val apiPort = settings.getInt(API_PORT_KEY, 443).coerceIn(1, 65535)
+        val rawCalls = settings.getInt(CALLS_PORT_KEY, -1)
+        val callsPort = if (rawCalls in 1..65535) rawCalls else DEFAULT_CALLS_PORT
+        val https = settings.getBoolean(HTTPS_ENABLED_KEY, true)
+        val callsEnabled =
+            if (settings.contains(CALLS_ENABLED_KEY)) {
+                settings.getBoolean(CALLS_ENABLED_KEY, true)
+            } else {
+                true
+            }
+        return ServerConfigData(
+            serverIp = ip,
+            apiPort = apiPort,
+            callsPort = callsPort,
+            httpsEnabled = https,
+            callsEnabled = callsEnabled,
+        )
+    }
+
+    private suspend fun writeServerConfig(value: ServerConfigData) {
+        settings.putString(SERVER_IP_KEY, value.serverIp.trim())
+        settings.putInt(API_PORT_KEY, value.apiPort.coerceIn(1, 65535))
+        settings.putInt(CALLS_PORT_KEY, value.callsPort.coerceIn(1, 65535))
+        settings.putBoolean(HTTPS_ENABLED_KEY, value.httpsEnabled)
+        settings.putBoolean(CALLS_ENABLED_KEY, value.callsEnabled)
+    }
 
     /** Cached device sessions (JSON). Shown immediately while refreshing from the network. */
     fun readDeviceSessionsCache(): List<DeviceSessionInfo>? = runBlocking {

app/shared/src/commonMain/kotlin/ru/fromchat/core/cache/CacheContext.kt

@@ -0,0 +1,47 @@
+package ru.fromchat.core.cache
+
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import ru.fromchat.api.ProfileCache
+import ru.fromchat.api.db.MessageDatabaseProvider
+import ru.fromchat.ui.chat.PublicChatPanelCache
+import ru.fromchat.ui.dm.DmPanelCache
+
+/**
+ * Active server instance partition for reads/writes.
+ * All repository queries must use [activeInstanceId] (non-empty when session is valid).
+ */
+object CacheContext {
+    private val _activeInstanceId = MutableStateFlow("")
+    val activeInstanceId: StateFlow<String> = _activeInstanceId.asStateFlow()
+
+    private val _activeUserId = MutableStateFlow<Int?>(null)
+    val activeUserId: StateFlow<Int?> = _activeUserId.asStateFlow()
+
+    fun setActiveInstance(instanceId: String, userId: Int?) {
+        val trimmed = instanceId.trim()
+        val changed = _activeInstanceId.value != trimmed
+        _activeInstanceId.value = trimmed
+        _activeUserId.value = userId
+        if (changed) {
+            ProfileCache.onActiveInstanceChanged(trimmed)
+            PublicChatPanelCache.onActiveInstanceChanged(trimmed)
+            DmPanelCache.onActiveInstanceChanged(trimmed)
+            if (trimmed.isNotEmpty()) {
+                MessageDatabaseProvider.rebindUnboundPartition(trimmed)
+            }
+        }
+    }
+
+    fun requireActiveInstanceId(): String {
+        val id = _activeInstanceId.value.trim()
+        require(id.isNotEmpty()) { "No active server instance id" }
+        return id
+    }
+
+    fun clearActive() {
+        _activeInstanceId.value = ""
+        _activeUserId.value = null
+    }
+}

app/shared/src/commonMain/kotlin/ru/fromchat/core/cache/CacheValidator.kt

@@ -0,0 +1,56 @@
+package ru.fromchat.core.cache
+
+import ru.fromchat.api.Message
+import ru.fromchat.api.db.GENERAL_PUBLIC_GROUP_ID
+import ru.fromchat.api.db.conversationIdForDm
+import ru.fromchat.api.db.conversationIdForGroup
+import ru.fromchat.api.db.dmOtherUserIdFromConversationId
+import ru.fromchat.api.db.groupIdFromConversationId
+
+/**
+ * In-partition validation so stale rows from a wrong server switch cannot render as trusted history.
+ */
+object CacheValidator {
+    fun filterMessages(
+        conversationId: String,
+        messages: List<Message>,
+        currentUserId: Int?,
+        dmPeerUserId: Int? = dmOtherUserIdFromConversationId(conversationId),
+    ): List<Message> = messages.filter { isMessageValid(it, conversationId, currentUserId, dmPeerUserId) }
+
+    fun isMessageValid(
+        message: Message,
+        conversationId: String,
+        currentUserId: Int?,
+        dmPeerUserId: Int? = dmOtherUserIdFromConversationId(conversationId),
+    ): Boolean {
+        val groupId = groupIdFromConversationId(conversationId)
+        if (groupId != null) {
+            if (groupId != GENERAL_PUBLIC_GROUP_ID) return false
+            return message.user_id > 0
+        }
+        val peer = dmPeerUserId ?: return false
+        val self = currentUserId ?: return false
+        if (message.user_id != self && message.user_id != peer) return false
+        if (message.id < 0 && message.client_message_id.isNullOrBlank()) return false
+        return true
+    }
+
+    /**
+     * Returns false when more than half of rows fail validation — caller should purge and refetch.
+     */
+    fun isConversationCacheCoherent(
+        conversationId: String,
+        messages: List<Message>,
+        currentUserId: Int?,
+    ): Boolean {
+        if (messages.isEmpty()) return true
+        val dmPeer = dmOtherUserIdFromConversationId(conversationId)
+        val valid = filterMessages(conversationId, messages, currentUserId, dmPeer)
+        return valid.size * 2 >= messages.size
+    }
+
+    fun conversationIdForDmPeer(otherUserId: Int): String = conversationIdForDm(otherUserId)
+
+    fun conversationIdForPublic(): String = conversationIdForGroup(GENERAL_PUBLIC_GROUP_ID)
+}

app/shared/src/commonMain/kotlin/ru/fromchat/core/cache/FromChatCacheDirs.kt

@@ -0,0 +1,4 @@
+package ru.fromchat.core.cache
+
+/** Deletes the `cacheDir/fromchat/` tree (blobs, DB file on disk). Call after [ru.fromchat.api.db.MessageRepository.clearAllCache]. */
+expect suspend fun wipeFromChatCacheDirectory()

app/shared/src/commonMain/kotlin/ru/fromchat/core/cache/FromChatCacheGeneration.kt

@@ -0,0 +1,8 @@
+package ru.fromchat.core.cache
+
+/**
+ * Detects OS "clear cache" (generation sentinel missing) and records a new generation after open.
+ */
+expect suspend fun ensureFromChatCacheGeneration()
+
+expect suspend fun writeFromChatCacheGeneration()

app/shared/src/commonMain/kotlin/ru/fromchat/core/cache/OutboundFileUnavailableException.kt

@@ -0,0 +1,16 @@
+package ru.fromchat.core.cache
+
+/** Original attachment URI is no longer readable (revoked permission, deleted file, etc.). */
+class OutboundFileUnavailableException(
+    message: String,
+    cause: Throwable? = null,
+) : Exception(message, cause)
+
+fun Throwable.isOutboundFileUnavailable(): Boolean {
+    var current: Throwable? = this
+    while (current != null) {
+        if (current is OutboundFileUnavailableException) return true
+        current = current.cause
+    }
+    return false
+}

app/shared/src/commonMain/kotlin/ru/fromchat/core/cache/ResumableUploadStorage.kt

@@ -0,0 +1,31 @@
+package ru.fromchat.core.cache
+
+data class StagedOutboundFile(
+    val uri: String,
+    val sizeBytes: Long,
+)
+
+/**
+ * Copies the picked attachment into instance-scoped cache so uploads survive process death.
+ */
+expect suspend fun stageOutboundFileForUpload(
+    instanceId: String,
+    clientMessageId: String,
+    sourceUri: String,
+): StagedOutboundFile
+
+/** Reads the picked attachment from a platform URI string. */
+expect suspend fun readOutboundFileBytes(fileUri: String): ByteArray
+
+expect suspend fun saveEncryptedUploadBlob(instanceId: String, clientMessageId: String, bytes: ByteArray)
+
+expect suspend fun loadEncryptedUploadBlob(instanceId: String, clientMessageId: String): ByteArray?
+
+expect suspend fun saveUploadTransportCipherJson(instanceId: String, clientMessageId: String, json: String)
+
+expect suspend fun loadUploadTransportCipherJson(instanceId: String, clientMessageId: String): String?
+
+expect suspend fun clearUploadArtifacts(instanceId: String, clientMessageId: String)
+
+/** Drops upload secrets and staging copy; keeps [DecryptedImageCache] files intact. */
+expect suspend fun clearUploadSecretsOnly(instanceId: String, clientMessageId: String)

app/shared/src/commonMain/kotlin/ru/fromchat/core/config/Config.kt

@@ -28,10 +28,10 @@ object Config {
     }
 
     /**
-     * Update server configuration
+     * Update server configuration (persists to storage before updating in-memory state).
      */
-    fun updateServerConfig(config: ServerConfigData) {
-        Settings.serverConfig = config
+    suspend fun updateServerConfig(config: ServerConfigData) {
+        Settings.setServerConfig(config)
         _serverConfig.value = config
     }
 

app/shared/src/commonMain/kotlin/ru/fromchat/core/instance/InstanceIdGuard.kt

@@ -0,0 +1,43 @@
+package ru.fromchat.core.instance
+
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.launch
+import kotlin.concurrent.Volatile
+import ru.fromchat.api.db.InstanceRegistryStore
+import ru.fromchat.core.ServerConfigData
+import ru.fromchat.core.cache.CacheContext
+
+/**
+ * Handles [INSTANCE_ID_HEADER] on API responses (main client + probe during server setup).
+ */
+object InstanceIdGuard {
+    const val INSTANCE_ID_HEADER = "X-FromChat-Instance-Id"
+
+    private val scope = CoroutineScope(SupervisorJob() + Dispatchers.Default)
+
+    @Volatile
+    var probeConfig: ServerConfigData? = null
+
+    fun onResponseHeader(headerValue: String?, config: ServerConfigData? = null) {
+        val raw = headerValue?.trim().orEmpty()
+        if (raw.isEmpty() || !isValidInstanceUuid(raw)) return
+        val cfg = config ?: probeConfig ?: return
+        scope.launch {
+            val bound = InstanceRegistryStore.getActiveInstanceIdForConfig(cfg)?.trim().orEmpty()
+            when {
+                bound.isEmpty() -> InstanceRegistryStore.rebindServerInstance(cfg, raw)
+                !bound.equals(raw, ignoreCase = true) ->
+                    InstanceRegistryStore.rebindServerInstanceOnMismatch(cfg, bound, raw)
+                else -> InstanceRegistryStore.registerInstanceEncountered(raw)
+            }
+            if (probeConfig == null && CacheContext.activeInstanceId.value.isNotEmpty()) {
+                val userId = CacheContext.activeUserId.value
+                if (!bound.equals(raw, ignoreCase = true)) {
+                    CacheContext.setActiveInstance(raw, userId)
+                }
+            }
+        }
+    }
+}

app/shared/src/commonMain/kotlin/ru/fromchat/core/instance/InstanceIdResolve.kt

@@ -0,0 +1,112 @@
+package ru.fromchat.core.instance
+
+import io.ktor.client.plugins.ClientRequestException
+import io.ktor.client.plugins.HttpRequestTimeoutException
+import io.ktor.client.network.sockets.ConnectTimeoutException
+import io.ktor.client.network.sockets.SocketTimeoutException
+import kotlinx.coroutines.TimeoutCancellationException
+import kotlinx.coroutines.withTimeout
+import ru.fromchat.api.ApiClient
+import ru.fromchat.api.db.InstanceRegistryStore
+import ru.fromchat.core.ServerConfigData
+import ru.fromchat.core.configKey
+
+private val UUID_REGEX =
+    Regex("^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$")
+
+fun isValidInstanceUuid(value: String): Boolean = UUID_REGEX.matches(value.trim())
+
+sealed interface InstanceIdResolveResult {
+    data class Cached(val instanceId: String) : InstanceIdResolveResult
+    data class Fetched(val instanceId: String) : InstanceIdResolveResult
+    data class InstanceIdChanged(val oldId: String, val newId: String) : InstanceIdResolveResult
+    data object Unsupported : InstanceIdResolveResult
+    data object Timeout : InstanceIdResolveResult
+    data object Unreachable : InstanceIdResolveResult
+}
+
+private const val INSTANCE_FETCH_MS = 10_000L
+
+/**
+ * Resolves instance id for [config]: reads DB binding, optionally fetches `/instance_id`.
+ * On mismatch with cached binding, rebinds via [InstanceRegistryStore] (no partition delete).
+ */
+suspend fun resolveInstanceId(
+    config: ServerConfigData,
+    apiBaseUrl: String,
+    forceNetwork: Boolean,
+): InstanceIdResolveResult {
+    val cached = InstanceRegistryStore.getActiveInstanceIdForConfig(config)?.trim().orEmpty()
+    if (!forceNetwork && cached.isNotEmpty() && isValidInstanceUuid(cached)) {
+        return InstanceIdResolveResult.Cached(cached)
+    }
+
+    val fetchResult = runCatching {
+        withTimeout(INSTANCE_FETCH_MS) {
+            ApiClient.fetchServerInstanceId(apiBaseUrl)
+        }
+    }
+    if (fetchResult.isFailure) {
+        return networkFailureToResolveResult(fetchResult.exceptionOrNull(), cached)
+    }
+    val fetched = fetchResult.getOrThrow().trim()
+
+    if (fetched.isEmpty() || !isValidInstanceUuid(fetched)) {
+        return InstanceIdResolveResult.Unsupported
+    }
+
+    if (cached.isEmpty()) {
+        InstanceRegistryStore.rebindServerInstance(config, fetched)
+        return InstanceIdResolveResult.Fetched(fetched)
+    }
+    if (cached.equals(fetched, ignoreCase = true)) {
+        InstanceRegistryStore.registerInstanceEncountered(fetched)
+        return InstanceIdResolveResult.Fetched(fetched)
+    }
+    InstanceRegistryStore.rebindServerInstanceOnMismatch(config, cached, fetched)
+    return InstanceIdResolveResult.InstanceIdChanged(cached, fetched)
+}
+
+fun apiBaseUrlFor(config: ServerConfigData): String {
+    val scheme = if (config.httpsEnabled) "https" else "http"
+    return "$scheme://${config.serverIp}:${config.apiPort}/api"
+}
+
+private fun networkFailureToResolveResult(
+    e: Throwable?,
+    cached: String,
+): InstanceIdResolveResult = when (e) {
+    is TimeoutCancellationException,
+    is HttpRequestTimeoutException,
+    is SocketTimeoutException,
+    -> {
+        if (cached.isNotEmpty() && isValidInstanceUuid(cached)) {
+            InstanceIdResolveResult.Cached(cached)
+        } else {
+            InstanceIdResolveResult.Timeout
+        }
+    }
+    is ConnectTimeoutException -> {
+        if (cached.isNotEmpty() && isValidInstanceUuid(cached)) {
+            InstanceIdResolveResult.Cached(cached)
+        } else {
+            InstanceIdResolveResult.Unreachable
+        }
+    }
+    is ClientRequestException -> {
+        if (e.response.status.value in 400..499) {
+            InstanceIdResolveResult.Unsupported
+        } else if (cached.isNotEmpty() && isValidInstanceUuid(cached)) {
+            InstanceIdResolveResult.Cached(cached)
+        } else {
+            InstanceIdResolveResult.Unreachable
+        }
+    }
+    else -> {
+        if (cached.isNotEmpty() && isValidInstanceUuid(cached)) {
+            InstanceIdResolveResult.Cached(cached)
+        } else {
+            InstanceIdResolveResult.Unreachable
+        }
+    }
+}

app/shared/src/commonMain/kotlin/ru/fromchat/core/instance/ServerConfigProbe.kt

@@ -0,0 +1,101 @@
+package ru.fromchat.core.instance
+
+import kotlin.time.TimeSource
+import kotlinx.coroutines.TimeoutCancellationException
+import kotlinx.coroutines.withTimeout
+import ru.fromchat.api.ApiClient
+import ru.fromchat.api.WebSocketManager
+import ru.fromchat.api.db.InstanceRegistryStore
+import ru.fromchat.core.ServerConfigData
+import ru.fromchat.core.cache.CacheContext
+import ru.fromchat.core.config.Config
+
+sealed interface ServerProbeResult {
+    data class Supported(
+        val instanceId: String,
+        val callsOk: Boolean,
+        val pingMs: Int,
+    ) : ServerProbeResult
+
+    data object Unsupported : ServerProbeResult
+    data object Timeout : ServerProbeResult
+    data object Unreachable : ServerProbeResult
+}
+
+private const val CALLS_PROBE_MS = 1_500L
+
+suspend fun probeCallsReachable(config: ServerConfigData): Boolean {
+    val urlScheme = if (config.httpsEnabled) "https" else "http"
+    val host = config.serverIp.trim()
+    val authorityHost = host.removePrefix("[").removeSuffix("]").ifEmpty { host }
+    val root = "$urlScheme://$authorityHost:${config.callsPort}/"
+    return runCatching {
+        withTimeout(CALLS_PROBE_MS) {
+            ApiClient.probeHttpGet(root)
+        }
+    }.getOrDefault(false)
+}
+
+suspend fun probeServer(config: ServerConfigData): ServerProbeResult {
+    val apiBase = apiBaseUrlFor(config)
+    val mark = TimeSource.Monotonic.markNow()
+    InstanceIdGuard.probeConfig = config
+    try {
+        val resolve = resolveInstanceId(config, apiBase, forceNetwork = true)
+        val pingMs = mark.elapsedNow().inWholeMilliseconds.toInt().coerceAtLeast(0)
+        val instanceId = when (resolve) {
+            is InstanceIdResolveResult.Cached -> resolve.instanceId
+            is InstanceIdResolveResult.Fetched -> resolve.instanceId
+            is InstanceIdResolveResult.InstanceIdChanged -> resolve.newId
+            InstanceIdResolveResult.Unsupported -> return ServerProbeResult.Unsupported
+            InstanceIdResolveResult.Timeout -> return ServerProbeResult.Timeout
+            InstanceIdResolveResult.Unreachable -> return ServerProbeResult.Unreachable
+        }
+        val callsOk = probeCallsReachable(config)
+        return ServerProbeResult.Supported(instanceId, callsOk, pingMs)
+    } finally {
+        InstanceIdGuard.probeConfig = null
+    }
+}
+
+suspend fun applyServerConfig(
+    config: ServerConfigData,
+    instanceId: String,
+    callsOk: Boolean,
+) {
+    val tentative = config.copy(callsEnabled = callsOk)
+    Config.updateServerConfig(tentative)
+    val userId = ApiClient.user?.id
+    InstanceRegistryStore.rebindServerInstance(tentative, instanceId)
+    CacheContext.setActiveInstance(instanceId, userId)
+}
+
+suspend fun applyServerAndNavigate(
+    probe: ServerProbeResult.Supported,
+    config: ServerConfigData,
+    bearer: String,
+    onNavigateLogin: suspend () -> Unit,
+    onNavigateChat: suspend () -> Unit,
+    onLogoutOldHost: suspend () -> Unit,
+) {
+    val apiBase = apiBaseUrlFor(config)
+    val token = bearer.trim()
+    if (token.isEmpty()) {
+        applyServerConfig(config, probe.instanceId, probe.callsOk)
+        WebSocketManager.disconnect()
+        onNavigateLogin()
+        return
+    }
+    val authOk = ApiClient.checkAuthAt(apiBase, token)
+    if (!authOk) {
+        onLogoutOldHost()
+        applyServerConfig(config, probe.instanceId, probe.callsOk)
+        WebSocketManager.disconnect()
+        onNavigateLogin()
+        return
+    }
+    applyServerConfig(config, probe.instanceId, probe.callsOk)
+    WebSocketManager.disconnect()
+    WebSocketManager.connect(forceRestart = true)
+    onNavigateChat()
+}

app/shared/src/commonMain/kotlin/ru/fromchat/core/instance/SessionInstanceBootstrap.kt

@@ -0,0 +1,62 @@
+package ru.fromchat.core.instance
+
+import ru.fromchat.api.ApiClient
+import ru.fromchat.api.db.InstanceRegistryStore
+import ru.fromchat.core.Settings
+import ru.fromchat.api.outbox.scheduleOutboxProcessing
+import ru.fromchat.core.cache.CacheContext
+import ru.fromchat.core.config.Config
+
+sealed interface SessionBootstrapResult {
+    data object Ready : SessionBootstrapResult
+    data object OfflineCached : SessionBootstrapResult
+    data object LogoutRequired : SessionBootstrapResult
+}
+
+/**
+ * Ensures [CacheContext] has an active instance for the current server config when a session exists.
+ */
+suspend fun bootstrapSessionInstance(hasToken: Boolean): SessionBootstrapResult {
+    if (!hasToken) return SessionBootstrapResult.Ready
+    val config = Settings.serverConfig
+    val apiBase = apiBaseUrlFor(config)
+    val resolve = resolveInstanceId(
+        config = config,
+        apiBaseUrl = apiBase,
+        forceNetwork = true,
+    )
+    return when (resolve) {
+        is InstanceIdResolveResult.Cached,
+        is InstanceIdResolveResult.Fetched,
+        is InstanceIdResolveResult.InstanceIdChanged,
+        -> {
+            val id = when (resolve) {
+                is InstanceIdResolveResult.Cached -> resolve.instanceId
+                is InstanceIdResolveResult.Fetched -> resolve.instanceId
+                is InstanceIdResolveResult.InstanceIdChanged -> resolve.newId
+            }
+            CacheContext.setActiveInstance(id, ApiClient.user?.id)
+            scheduleOutboxProcessing(id)
+            SessionBootstrapResult.Ready
+        }
+        InstanceIdResolveResult.Timeout,
+        InstanceIdResolveResult.Unreachable,
+        -> {
+            val cached = InstanceRegistryStore.getActiveInstanceIdForConfig(config)?.trim().orEmpty()
+            if (cached.isNotEmpty() && isValidInstanceUuid(cached)) {
+                CacheContext.setActiveInstance(cached, ApiClient.user?.id)
+                scheduleOutboxProcessing(cached)
+                SessionBootstrapResult.OfflineCached
+            } else {
+                SessionBootstrapResult.OfflineCached
+            }
+        }
+        InstanceIdResolveResult.Unsupported -> SessionBootstrapResult.LogoutRequired
+    }
+}
+
+suspend fun logoutIfInstanceUnsupported() {
+    runCatching { ApiClient.logout() }
+    ApiClient.clearMemorySession()
+    CacheContext.clearActive()
+}

app/shared/src/commonMain/kotlin/ru/fromchat/crypto/DmCrypto.kt

@@ -57,7 +57,9 @@ suspend fun decryptEnvelope(envelope: DmEnvelope, currentUserId: Int?): String {
 suspend fun decryptFile(
     file: ru.fromchat.api.DmFile,
     envelope: DmEnvelope,
-    currentUserId: Int?
+    currentUserId: Int?,
+    downloadResumeKey: String? = null,
+    onDownloadProgress: ((Int) -> Unit)? = null,
 ): ByteArray {
     val wrappedMekB64 = file.wrappedMekB64
         ?: envelope.files?.find { it.path == file.path }?.wrappedMekB64
@@ -68,7 +70,18 @@ suspend fun decryptFile(
         ?: throw IllegalArgumentException("No nonce available for file decryption: ${file.path}")
 
     val mek = unwrapMek(wrappedMekB64, envelope, currentUserId)
-    val encryptedBytes = ru.fromchat.api.ApiClient.fetchEncryptedFile(file.path)
-    val ciphertextB64 = com.pr0gramm3r101.utils.crypto.Base64.encode(encryptedBytes)
-    return DmCrypto.decryptEnvelope(nonceB64, ciphertextB64, mek)
+    ru.fromchat.core.Logger.d("DmCrypto", "fetchEncryptedFile path=${file.path}")
+    val encryptedBytes = if (downloadResumeKey != null) {
+        ru.fromchat.api.ApiClient.fetchEncryptedFileResumable(
+            path = file.path,
+            resumeKey = downloadResumeKey,
+            onProgress = onDownloadProgress,
+        )
+    } else {
+        ru.fromchat.api.ApiClient.fetchEncryptedFile(file.path)
+    }
+    if (encryptedBytes.isEmpty()) {
+        throw IllegalArgumentException("Encrypted file is empty: ${file.path}")
+    }
+    return DmCrypto.decryptAesGcm(nonceB64, encryptedBytes, mek)
 }

app/shared/src/commonMain/kotlin/ru/fromchat/crypto/dm/DmCrypto.kt

@@ -28,4 +28,7 @@ expect object DmCrypto {
      * @return Decrypted plaintext
      */
     suspend fun decryptEnvelope(ivB64: String, ciphertextB64: String, mek: ByteArray): ByteArray
+
+    /** AES-GCM decrypt downloaded file bytes (ciphertext + tag; IV from [ivB64]). */
+    suspend fun decryptAesGcm(ivB64: String, ciphertext: ByteArray, mek: ByteArray): ByteArray
 }

app/shared/src/commonMain/kotlin/ru/fromchat/ui/App.kt

@@ -58,7 +58,11 @@ import ru.fromchat.api.UserStatusStore
 import ru.fromchat.api.WebSocketManager
 import ru.fromchat.api.WebSocketMessage
 import ru.fromchat.api.WebSocketUpdatesData
+import ru.fromchat.api.outbox.OutgoingMessageCoordinator
+import ru.fromchat.api.outbox.scheduleOutboxProcessing
+import ru.fromchat.core.cache.CacheContext
 import ru.fromchat.core.Logger
+import ru.fromchat.core.cache.ensureFromChatCacheGeneration
 import ru.fromchat.core.config.Config
 import ru.fromchat.net.NetworkConnectivity
 import ru.fromchat.ui.auth.LoginScreen
@@ -191,11 +195,27 @@ fun App(
             Config.initialize()
         }
 
+        runCatching { ensureFromChatCacheGeneration() }
+
         runCatching { NetworkConnectivity.ensureStarted() }
 
         // Load persisted token and user data
         ApiClient.loadPersistedData()
 
+        val hasTokenForBootstrap = ApiClient.token?.isNotEmpty() == true
+        if (hasTokenForBootstrap) {
+            when (ru.fromchat.core.instance.bootstrapSessionInstance(hasToken = true)) {
+                ru.fromchat.core.instance.SessionBootstrapResult.LogoutRequired -> {
+                    ru.fromchat.core.instance.logoutIfInstanceUnsupported()
+                    startDestination = "login"
+                    return@LaunchedEffect
+                }
+                ru.fromchat.core.instance.SessionBootstrapResult.OfflineCached,
+                ru.fromchat.core.instance.SessionBootstrapResult.Ready,
+                -> Unit
+            }
+        }
+
         runCatching { ProfileCache.hydrateFromDisk() }
 
         val hasTokenInitially = ApiClient.token?.isNotEmpty() == true
@@ -235,6 +255,15 @@ fun App(
                 Lifecycle.Event.ON_START -> {
                     AppForeground.setForeground(true)
                     WebSocketManager.connect()
+                    MainScope().launch {
+                        val instanceId = CacheContext.activeInstanceId.value.trim()
+                        if (instanceId.isNotEmpty()) {
+                            scheduleOutboxProcessing(instanceId)
+                            kotlinx.coroutines.withContext(kotlinx.coroutines.Dispatchers.Default) {
+                                OutgoingMessageCoordinator.drainOutboxForInstance(instanceId)
+                            }
+                        }
+                    }
                 }
                 Lifecycle.Event.ON_STOP -> AppForeground.setForeground(false)
                 else -> {}

app/shared/src/commonMain/kotlin/ru/fromchat/ui/chat/AttachmentDownloadScheduler.kt

@@ -0,0 +1,108 @@
+package ru.fromchat.ui.chat
+
+import kotlinx.coroutines.CompletableDeferred
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
+
+/**
+ * Limits concurrent DM attachment decrypt/download work to [MAX_PARALLEL].
+ * Additional requests wait in a priority queue (visible messages first).
+ */
+object AttachmentDownloadScheduler {
+    private const val MAX_PARALLEL = 2
+
+    private val scope = CoroutineScope(SupervisorJob() + Dispatchers.Default)
+    private val mutex = Mutex()
+
+    private data class Pending(
+        val storageKey: String,
+        val messageId: Int,
+        val enqueuedAt: Long,
+        val work: suspend () -> String?,
+        val result: CompletableDeferred<String?>,
+    )
+
+    private val waiting = mutableListOf<Pending>()
+    private val keyToDeferred = mutableMapOf<String, CompletableDeferred<String?>>()
+    private var activeCount = 0
+
+    /**
+     * Runs [work] when a download slot is available. Duplicate [storageKey] shares one result.
+     */
+    suspend fun run(
+        storageKey: String,
+        messageId: Int,
+        work: suspend () -> String?,
+    ): String? {
+        val deferred = mutex.withLock {
+            keyToDeferred[storageKey] ?: run {
+                val created = CompletableDeferred<String?>()
+                keyToDeferred[storageKey] = created
+                waiting.add(
+                    Pending(
+                        storageKey = storageKey,
+                        messageId = messageId,
+                        enqueuedAt = AttachmentMediaLog.nowMs(),
+                        work = work,
+                        result = created,
+                    ),
+                )
+                sortWaitingLocked()
+                created
+            }
+        }
+        pumpLocked()
+        return deferred.await()
+    }
+
+    fun reprioritize() {
+        scope.launch {
+            mutex.withLock {
+                sortWaitingLocked()
+            }
+            pumpLocked()
+        }
+    }
+
+    private suspend fun pumpLocked() {
+        val toStart = mutex.withLock {
+            val jobs = mutableListOf<Pending>()
+            while (activeCount < MAX_PARALLEL && waiting.isNotEmpty()) {
+                val next = waiting.removeAt(0)
+                activeCount++
+                jobs.add(next)
+            }
+            jobs
+        }
+        for (pending in toStart) {
+            scope.launch {
+                runPending(pending)
+            }
+        }
+    }
+
+    private suspend fun runPending(pending: Pending) {
+        val outcome = runCatching { pending.work() }
+        mutex.withLock {
+            activeCount = (activeCount - 1).coerceAtLeast(0)
+            keyToDeferred.remove(pending.storageKey)
+        }
+        outcome.fold(
+            onSuccess = { pending.result.complete(it) },
+            onFailure = { pending.result.completeExceptionally(it) },
+        )
+        pumpLocked()
+    }
+
+    private fun sortWaitingLocked() {
+        waiting.sortWith(
+            compareBy<Pending> { pending ->
+                if (AttachmentDownloadVisibility.isPrioritized(pending.messageId)) 0 else 1
+            }.thenBy { it.enqueuedAt },
+        )
+    }
+}

app/shared/src/commonMain/kotlin/ru/fromchat/ui/chat/AttachmentDownloadVisibility.kt

@@ -0,0 +1,40 @@
+package ru.fromchat.ui.chat
+
+import androidx.compose.foundation.lazy.LazyListState
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import ru.fromchat.api.Message
+
+/** Visible chat message ids (from [LazyListState]); used to prioritize attachment downloads. */
+object AttachmentDownloadVisibility {
+    private val _visibleMessageIds = MutableStateFlow<Set<Int>>(emptySet())
+
+    val visibleMessageIds: StateFlow<Set<Int>> = _visibleMessageIds.asStateFlow()
+
+    fun setVisibleMessageIds(ids: Set<Int>) {
+        if (_visibleMessageIds.value == ids) return
+        _visibleMessageIds.value = ids
+        AttachmentDownloadScheduler.reprioritize()
+    }
+
+    fun isPrioritized(messageId: Int): Boolean =
+        messageId != 0 && messageId in _visibleMessageIds.value
+}
+
+/** Maps reverse-layout chat list indices to message ids (index 0 = bottom spacer). */
+fun visibleMessageIdsInChatList(
+    listState: LazyListState,
+    messages: List<Message>,
+    extraMessageId: Int? = null,
+): Set<Int> {
+    val reversed = messages.asReversed()
+    val ids = listState.layoutInfo.visibleItemsInfo.mapNotNull { info ->
+        val lazyIndex = info.index
+        if (lazyIndex <= 0) null else reversed.getOrNull(lazyIndex - 1)?.id
+    }.toMutableSet()
+    if (extraMessageId != null && extraMessageId != 0) {
+        ids.add(extraMessageId)
+    }
+    return ids
+}

app/shared/src/commonMain/kotlin/ru/fromchat/ui/chat/AttachmentImageGeometry.kt

@@ -0,0 +1,63 @@
+package ru.fromchat.ui.chat
+
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.dp
+
+/** Bubble top radius (must match [ru.fromchat.ui.chat.MessageItem] bubble shape). */
+private val BUBBLE_TOP = 20.dp
+
+/** Padding between bubble edge and attachment image (must match MessageItem image padding). */
+internal val ATTACHMENT_IMAGE_INSET = 2.dp
+
+/** Slight rounding on image preview bottom corners (less than bubble). */
+private val IMAGE_BOTTOM_CORNER = 4.dp
+
+/** Inner clip: top corners follow bubble minus inset; bottom corners lightly rounded. */
+@Suppress("UNUSED_PARAMETER")
+internal fun attachmentImageCornerShape(isAuthor: Boolean): RoundedCornerShape {
+    val inset = ATTACHMENT_IMAGE_INSET
+    return RoundedCornerShape(
+        topStart = (BUBBLE_TOP - inset).coerceAtLeast(0.dp),
+        topEnd = (BUBBLE_TOP - inset).coerceAtLeast(0.dp),
+        bottomStart = IMAGE_BOTTOM_CORNER,
+        bottomEnd = IMAGE_BOTTOM_CORNER,
+    )
+}
+
+/** Width / height for layout and decode. Pixel dimensions and server ratios beat stale pending. */
+internal fun imageAspectRatioForMessage(
+    fileAspectRatios: List<Float>?,
+    fileDimensions: List<Pair<Int, Int>>?,
+    pendingFileAspectRatio: Float?,
+    fileIndex: Int = 0,
+    @Suppress("UNUSED_PARAMETER") confirmed: Boolean = true,
+    @Suppress("UNUSED_PARAMETER") hasLocalPreview: Boolean = false,
+): Float? {
+    fileDimensions?.getOrNull(fileIndex)?.let { (w, h) ->
+        if (w > 0 && h > 0) {
+            return ru.fromchat.api.db.aspectRatioFromDimensionPair(w, h)
+        }
+    }
+    fileAspectRatios?.getOrNull(fileIndex)?.takeIf { it > 0f }?.let { return it }
+    return pendingFileAspectRatio?.takeIf { fileIndex == 0 && it > 0f }
+}
+
+internal fun coalesceDecodeTarget(vararg sizes: ChatPreviewDecodeSize?): ChatPreviewDecodeSize {
+    val present = sizes.filterNotNull()
+    require(present.isNotEmpty())
+    return ChatPreviewDecodeSize(
+        widthPx = present.maxOf { it.widthPx },
+        heightPx = present.maxOf { it.heightPx },
+    )
+}
+
+internal fun decodeSizeChangedMeaningfully(
+    previous: ChatPreviewDecodeSize?,
+    measured: ChatPreviewDecodeSize,
+): Boolean {
+    if (previous == null) return true
+    val wRatio = measured.widthPx.toFloat() / previous.widthPx.toFloat()
+    val hRatio = measured.heightPx.toFloat() / previous.heightPx.toFloat()
+    return wRatio > 1.12f || hRatio > 1.12f || wRatio < 0.88f || hRatio < 0.88f
+}

app/shared/src/commonMain/kotlin/ru/fromchat/ui/chat/AttachmentMediaLog.kt

@@ -0,0 +1,39 @@
+package ru.fromchat.ui.chat
+
+import kotlin.time.Clock
+import ru.fromchat.core.Logger
+
+/**
+ * Unified filter tag for attachment media pipeline (upload, download, disk/bitmap cache, tile decode).
+ * Logcat: `adb logcat -s AttachmentMedia` or filter `AttachmentMedia` in Android Studio.
+ */
+object AttachmentMediaLog {
+    const val TAG = "AttachmentMedia"
+
+    fun upload(message: String, vararg fields: Pair<String, Any?>) = log("UPLOAD", message, fields)
+
+    fun download(message: String, vararg fields: Pair<String, Any?>) = log("DOWNLOAD", message, fields)
+
+    fun diskCache(message: String, vararg fields: Pair<String, Any?>) = log("DISK", message, fields)
+
+    fun bitmapCache(message: String, vararg fields: Pair<String, Any?>) = log("BITMAP", message, fields)
+
+    fun tileLoad(message: String, vararg fields: Pair<String, Any?>) = log("TILE", message, fields)
+
+    fun persist(message: String, vararg fields: Pair<String, Any?>) = log("PERSIST", message, fields)
+
+    fun nowMs(): Long = Clock.System.now().toEpochMilliseconds()
+
+    /** Short message text for download/upload log lines (not for UI). */
+    fun messageLabel(content: String?, maxLen: Int = 64): String? =
+        content?.trim()?.take(maxLen)?.takeIf { it.isNotEmpty() }
+
+    private fun log(subsystem: String, message: String, fields: Array<out Pair<String, Any?>>) {
+        val suffix = if (fields.isEmpty()) {
+            ""
+        } else {
+            " | " + fields.joinToString(" ") { (k, v) -> "$k=$v" }
+        }
+        Logger.d(TAG, "[$subsystem] $message$suffix")
+    }
+}

app/shared/src/commonMain/kotlin/ru/fromchat/ui/chat/AttachmentPickers.kt

@@ -31,3 +31,6 @@ expect fun getFilenameFromUri(uri: String): String
 
 /** Get image aspect ratio (width/height) from URI without loading full image. Returns null if unavailable. */
 expect suspend fun getImageAspectRatio(uri: String): Float?
+
+/** Pixel width/height after EXIF orientation, or null if unavailable. */
+expect suspend fun getImageDimensions(uri: String): Pair<Int, Int>?

app/shared/src/commonMain/kotlin/ru/fromchat/ui/chat/AttachmentPreview.kt

@@ -42,19 +42,31 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.key
+import androidx.compose.runtime.mutableIntStateOf
 import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.produceState
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
+import androidx.compose.material3.TextButton
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.coroutineScope
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.semantics.contentDescription
+import androidx.compose.ui.semantics.semantics
 import androidx.compose.ui.draw.alpha
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.geometry.Rect
 import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.ImageBitmap
 import androidx.compose.ui.graphics.graphicsLayer
 import androidx.compose.ui.layout.ContentScale
 import androidx.compose.ui.layout.onGloballyPositioned
 import androidx.compose.ui.layout.positionInRoot
+import androidx.compose.ui.unit.IntSize
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import coil3.compose.AsyncImage
@@ -64,11 +76,18 @@ import com.pr0gramm3r101.utils.crypto.Base64
 import dev.chrisbanes.haze.hazeEffect
 import dev.chrisbanes.haze.materials.ExperimentalHazeMaterialsApi
 import dev.chrisbanes.haze.materials.HazeMaterials
+import org.jetbrains.compose.resources.stringResource
+import ru.fromchat.Res
+import ru.fromchat.api.ApiClient
+import ru.fromchat.api.AttachmentDownloadNotifier
 import ru.fromchat.api.DmEnvelope
 import ru.fromchat.api.DmFile
+import ru.fromchat.attachment_image_load_failed
+import ru.fromchat.attachment_retry
+import ru.fromchat.cd_attachment_retry
 
 private val IMAGE_SIZE = 160.dp
-private val IMAGE_RADIUS = 12.dp
+private const val BLUR_FADE_MS = 450
 
 internal fun isImageFilename(name: String): Boolean =
     name.endsWith(".png", true) || name.endsWith(".jpg", true) ||
@@ -84,6 +103,8 @@ fun AttachmentPreview(
     /** Filename for pending (non-image) files; used when pendingFileUri is set. */
     pendingFilename: String? = null,
     isUploading: Boolean,
+    /** Waiting for server ack after upload finished (keep blur, no progress ring). */
+    awaitingServerAck: Boolean = false,
     /** 0–100 upload progress when isUploading; null = indefinite */
     uploadProgress: Int? = null,
     fileThumbnail: String? = null,
@@ -91,11 +112,14 @@ fun AttachmentPreview(
     fileSizeBytes: Long? = null,
     messageId: Int? = null,
     fileIndex: Int? = null,
+    clientMessageId: String? = null,
     onFileClick: (() -> Unit)? = null,
     onImageClick: (() -> Unit)? = null,
     onImageBounds: ((Rect) -> Unit)? = null,
     isExpanded: Boolean = false,
     isAuthor: Boolean = false,
+    /** Message text shown in attachment download/upload logs. */
+    messageLabel: String? = null,
     modifier: Modifier = Modifier
 ) {
     val isImage = when {
@@ -108,8 +132,9 @@ fun AttachmentPreview(
         else -> false
     }
 
-    val isImageWithThumb = file != null && isImage && dmEnvelope != null && !fileThumbnail.isNullOrBlank()
-    val isPendingImage = pendingFileUri != null && isImage
+    val isPendingImage = pendingFileUri != null && isImage && file == null && dmEnvelope == null
+    val isConfirmedImage = file != null && isImage && dmEnvelope != null && !isPendingImage
+    val showImageTile = isPendingImage || isConfirmedImage
     val isPendingFile = pendingFileUri != null && !isImage
 
     when {
@@ -124,20 +149,29 @@ fun AttachmentPreview(
                 sizeBytes = fileSizeBytes,
                 onClick = if (file != null) onFileClick else null,
                 isAuthor = isAuthor,
-                isUploading = isPendingFile && isUploading,
+                isUploading = isPendingFile && (isUploading || awaitingServerAck),
                 uploadProgress = if (isPendingFile) uploadProgress else null,
                 modifier = modifier
             )
         }
-        isImageWithThumb || isPendingImage -> {
+        showImageTile -> {
             var isFullyLoaded by remember(messageId, fileIndex, file?.path, pendingFileUri) {
                 mutableStateOf(false)
             }
             Box(
                 modifier = modifier
                     .then(
-                        if (onImageClick != null && isFullyLoaded && !isExpanded && (isImageWithThumb || !isPendingImage)) Modifier.clickable(indication = null, interactionSource = remember { MutableInteractionSource() }, onClick = onImageClick)
-                        else Modifier
+                        if (onImageClick != null && !isExpanded &&
+                            (isPendingImage || isFullyLoaded || pendingFileUri != null)
+                        ) {
+                            Modifier.clickable(
+                                indication = null,
+                                interactionSource = remember { MutableInteractionSource() },
+                                onClick = onImageClick,
+                            )
+                        } else {
+                            Modifier
+                        }
                     )
                     .conditional(
                         fileAspectRatio != null && fileAspectRatio > 0f,
@@ -150,9 +184,9 @@ fun AttachmentPreview(
                             Modifier.size(IMAGE_SIZE)
                         }
                     )
-                    .clip(RoundedCornerShape(IMAGE_RADIUS))
+                    .clip(attachmentImageCornerShape(isAuthor))
                     .then(
-                        if (onImageBounds != null && (isImageWithThumb || !isPendingImage)) {
+                        if (onImageBounds != null && showImageTile) {
                             Modifier.onGloballyPositioned { coords ->
                                 val pos = coords.positionInRoot()
                                 val size = coords.size
@@ -176,27 +210,26 @@ fun AttachmentPreview(
                         .fillMaxSize()
                         .graphicsLayer { alpha = if (isExpanded) 0f else 1f }
                 ) {
-                    when {
-                        isPendingImage -> UnifiedImageContent(
-                            localUri = pendingFileUri,
-                            messageId = messageId,
-                            fileIndex = fileIndex,
-                            file = file,
-                            envelope = dmEnvelope,
-                            currentUserId = currentUserId,
-                            isUploading = isUploading,
-                            uploadProgress = uploadProgress,
-                            onFullyLoaded = { if (it) isFullyLoaded = true }
-                        )
-                        else -> DecryptedImageContent(
+                    val imageStableKey = clientMessageId?.trim()?.takeIf { it.isNotEmpty() }
+                        ?: "img:${messageId ?: 0}:${fileIndex ?: 0}"
+                    key(imageStableKey) {
+                        ChatImageTileContent(
                             messageId = messageId ?: -1,
                             fileIndex = fileIndex ?: 0,
-                            file = file!!,
-                            envelope = dmEnvelope!!,
-                            currentUserId = currentUserId,
-                            thumbnailBase64 = fileThumbnail!!,
+                            clientMessageId = clientMessageId,
+                            localUri = pendingFileUri,
+                            serverFile = file,
+                            envelope = dmEnvelope,
+                            thumbnailBase64 = fileThumbnail,
                             aspectRatio = fileAspectRatio,
-                            onFullyLoaded = { if (it) isFullyLoaded = true }
+                            currentUserId = currentUserId,
+                            isAuthor = isAuthor,
+                            isOutboundPending = isPendingImage,
+                            isUploading = isUploading,
+                            awaitingServerAck = awaitingServerAck,
+                            uploadProgress = uploadProgress,
+                            messageLabel = messageLabel,
+                            onFullyLoaded = { if (it) isFullyLoaded = true },
                         )
                     }
                 }
@@ -207,104 +240,438 @@ fun AttachmentPreview(
 
 @OptIn(ExperimentalHazeMaterialsApi::class, ExperimentalMaterial3ExpressiveApi::class)
 @Composable
-private fun UnifiedImageContent(
-    localUri: String,
-    messageId: Int?,
-    fileIndex: Int?,
-    file: DmFile?,
+private fun ChatImageTileContent(
+    messageId: Int,
+    fileIndex: Int,
+    clientMessageId: String?,
+    localUri: String?,
+    serverFile: DmFile?,
     envelope: DmEnvelope?,
+    thumbnailBase64: String?,
+    aspectRatio: Float?,
     currentUserId: Int?,
+    isAuthor: Boolean,
+    isOutboundPending: Boolean,
     isUploading: Boolean,
+    awaitingServerAck: Boolean,
     uploadProgress: Int?,
-    onFullyLoaded: (Boolean) -> Unit = {}
+    messageLabel: String? = null,
+    onFullyLoaded: (Boolean) -> Unit = {},
 ) {
-    var cachedPath by remember(messageId, fileIndex, file?.path) {
-        mutableStateOf(
-            if (messageId != null && fileIndex != null && file != null) {
-                DecryptedImageCache.getCached(messageId, fileIndex, file.path)
-            } else {
-                null
-            }
-        )
+    val clipShape = attachmentImageCornerShape(isAuthor)
+    val cacheClientId = clientMessageId?.trim()?.takeIf { it.isNotEmpty() }
+    val layoutAspect = aspectRatio?.takeIf { it.isFinite() && it > 0f }
+    val fallbackDecodeSize = rememberChatPreviewDecodeSize(IMAGE_SIZE, layoutAspect)
+    val seedDecodeSize = remember(layoutAspect) { previewSeedDecodeSize(layoutAspect) }
+    val decryptCacheKey = remember(messageId, fileIndex, cacheClientId) {
+        DecryptedImageCache.storageKey(messageId, fileIndex, cacheClientId)
+    }
+    var tileDecodeSize by remember(decryptCacheKey) { mutableStateOf<ChatPreviewDecodeSize?>(null) }
+    val decodeSize = remember(tileDecodeSize, fallbackDecodeSize, seedDecodeSize) {
+        coalesceDecodeTarget(tileDecodeSize, fallbackDecodeSize, seedDecodeSize)
     }
 
-    LaunchedEffect(messageId, fileIndex, file?.path, envelope) {
-        cachedPath = if (messageId != null && fileIndex != null && file != null && envelope != null) {
-            DecryptedImageCache.getOrDecrypt(messageId, fileIndex, file, envelope, currentUserId)
+    val initialFull = remember(decryptCacheKey) { LocalDecodedImageCache.peekFull(decryptCacheKey) }
+    val hadInstantFull = initialFull != null
+    val hasLocalSource = !localUri.isNullOrBlank()
+    val hasServerThumb = thumbnailBase64?.isNotBlank() == true
+
+    var fullBitmap by remember(decryptCacheKey) {
+        mutableStateOf(initialFull)
+    }
+    var didRevealFull by remember(decryptCacheKey) { mutableStateOf(hadInstantFull) }
+    val thumbBlurAlpha = remember(decryptCacheKey, hasServerThumb, hasLocalSource) {
+        Animatable(
+            when {
+                hadInstantFull -> 0f
+                hasServerThumb || hasLocalSource -> 1f
+                else -> 0f
+            },
+        )
+    }
+    val fullRevealAlpha = remember(decryptCacheKey) {
+        Animatable(if (hadInstantFull) 1f else 0f)
+    }
+    val showOutboundBlurOverlay = isOutboundPending && hasLocalSource
+    val outboundOverlayAlpha = remember(showOutboundBlurOverlay) {
+        Animatable(if (showOutboundBlurOverlay) 1f else 0f)
+    }
+    val downloadProgressByKey by AttachmentDownloadNotifier.progressPercentByKey.collectAsState()
+    val downloadProgress = remember(downloadProgressByKey, messageId, fileIndex, cacheClientId) {
+        DecryptedImageCache.resolveDownloadPercent(
+            messageId = messageId,
+            fileIndex = fileIndex,
+            clientMessageId = cacheClientId,
+            progressByKey = downloadProgressByKey,
+        )
+    }
+    val decryptFailed = remember(downloadProgressByKey, messageId, fileIndex, cacheClientId) {
+        AttachmentDownloadNotifier.isFailed(messageId, fileIndex, cacheClientId)
+    }
+    var isAwaitingNetworkFull by remember(decryptCacheKey) { mutableStateOf(false) }
+    var loadAttempt by remember(decryptCacheKey) { mutableIntStateOf(0) }
+    LaunchedEffect(showOutboundBlurOverlay) {
+        if (showOutboundBlurOverlay) {
+            outboundOverlayAlpha.snapTo(1f)
         } else {
-            null
+            if (fullBitmap != null) {
+                didRevealFull = true
+                fullRevealAlpha.snapTo(1f)
+                thumbBlurAlpha.snapTo(0f)
+            }
+            outboundOverlayAlpha.animateTo(0f, tween(BLUR_FADE_MS, easing = FastOutSlowInEasing))
         }
     }
 
-    val localPainter = rememberAsyncImagePainter(
-        model = localUri,
-        contentScale = ContentScale.Crop
-    )
-    val localState by localPainter.state.collectAsState()
-    LaunchedEffect(localState) {
-        if (localState is coil3.compose.AsyncImagePainter.State.Success) {
+    var cachedPath by remember(decryptCacheKey) {
+        mutableStateOf(DecryptedImageCache.getCached(messageId, fileIndex, cacheClientId))
+    }
+    val thumbnailBytes = remember(thumbnailBase64) {
+        thumbnailBase64?.let { decodeAttachmentThumbnailBase64(it) }
+    }
+    val thumbBitmap by produceState<ImageBitmap?>(
+        initialValue = LocalDecodedImageCache.peekThumb(decryptCacheKey),
+        decryptCacheKey,
+        thumbnailBytes,
+        decodeSize,
+    ) {
+        if (thumbnailBytes == null) {
+            value = null
+            return@produceState
+        }
+        value = LocalDecodedImageCache.peekThumb(decryptCacheKey)
+            ?: withContext(Dispatchers.Default) {
+                LocalDecodedImageCache.loadThumb(decryptCacheKey, thumbnailBytes, decodeSize)
+            }
+    }
+    var decryptFinished by remember(decryptCacheKey) {
+        mutableStateOf(fullBitmap != null)
+    }
+    val imageContentScale = ContentScale.Fit
+    val tilePlaceholderColor = MaterialTheme.colorScheme.surfaceContainerHigh.copy(alpha = 0.42f)
+
+    LaunchedEffect(
+        decryptCacheKey,
+        localUri,
+        serverFile?.path,
+        messageId,
+        isOutboundPending,
+        cacheClientId,
+        loadAttempt,
+    ) {
+        val target = decodeSize
+        AttachmentMediaLog.tileLoad(
+            "load_start",
+            "key" to decryptCacheKey,
+            "msgId" to messageId,
+            "pending" to isOutboundPending,
+            "localUri" to (localUri?.take(48) ?: "null"),
+            "target" to "${target.widthPx}x${target.heightPx}",
+        )
+        val diskUri = DecryptedImageCache.getCached(messageId, fileIndex, cacheClientId)
+        val localPaths = buildList {
+            localUri?.trim()?.takeIf { it.isNotEmpty() }?.let { add(it) }
+            diskUri?.let { cached -> if (none { it == cached }) add(cached) }
+        }
+        if (localPaths.isNotEmpty()) {
+            val loaded = withContext(Dispatchers.Default) {
+                LocalDecodedImageCache.peekFull(decryptCacheKey)
+                    ?: localPaths.firstNotNullOfOrNull { path ->
+                        LocalDecodedImageCache.loadFull(
+                            decryptCacheKey,
+                            path.removePrefix("file://"),
+                            target,
+                        )
+                    }
+            }
+            if (loaded != null) {
+                AttachmentMediaLog.tileLoad(
+                    "load_local_ok",
+                    "key" to decryptCacheKey,
+                    "source" to "disk_or_pending",
+                    "bmp" to "${loaded.width}x${loaded.height}",
+                )
+                fullBitmap = loaded
+                cachedPath = diskUri ?: localPaths.firstOrNull()
+                decryptFinished = true
+                if (thumbBitmap == null) {
+                    didRevealFull = true
+                    fullRevealAlpha.snapTo(1f)
+                    thumbBlurAlpha.snapTo(0f)
+                }
+            onFullyLoaded(true)
+                return@LaunchedEffect
+            }
+            AttachmentMediaLog.tileLoad(
+                "load_local_miss",
+                "key" to decryptCacheKey,
+                "paths" to localPaths.size,
+            )
+        }
+        if (isOutboundPending) {
+            decryptFinished = localPaths.isEmpty() && thumbBitmap == null && thumbnailBytes == null
+            if (fullBitmap != null || thumbBitmap != null) onFullyLoaded(true)
+            return@LaunchedEffect
+        }
+        val file = serverFile
+        val env = envelope
+        if (file == null || env == null) {
+            decryptFinished = true
+            AttachmentMediaLog.tileLoad("load_skip_no_envelope", "key" to decryptCacheKey)
+            return@LaunchedEffect
+        }
+        if (diskUri != null) {
+            cachedPath = diskUri
+            val loaded = withContext(Dispatchers.Default) {
+                LocalDecodedImageCache.loadFull(decryptCacheKey, diskUri.removePrefix("file://"), target)
+            }
+            if (loaded != null) {
+                AttachmentMediaLog.tileLoad(
+                    "load_disk_decode_ok",
+                    "key" to decryptCacheKey,
+                    "uri" to diskUri,
+                    "bmp" to "${loaded.width}x${loaded.height}",
+                )
+                fullBitmap = loaded
+                decryptFinished = true
+                if (thumbBitmap == null) {
+                    didRevealFull = true
+                    fullRevealAlpha.snapTo(1f)
+                    thumbBlurAlpha.snapTo(0f)
+                }
+                onFullyLoaded(true)
+                return@LaunchedEffect
+            }
+            AttachmentMediaLog.tileLoad(
+                "load_disk_decode_failed",
+                "key" to decryptCacheKey,
+                "uri" to diskUri,
+            )
+        }
+        AttachmentMediaLog.tileLoad(
+            "load_network_decrypt",
+            "key" to decryptCacheKey,
+            "file" to file.path,
+        )
+        isAwaitingNetworkFull = true
+        val uri = try {
+            DecryptedImageCache.getOrDecrypt(
+                messageId = messageId,
+                fileIndex = fileIndex,
+                file = file,
+                envelope = env,
+                currentUserId = currentUserId,
+                clientMessageId = cacheClientId,
+                messageLabel = messageLabel,
+            )
+        } catch (error: Throwable) {
+            AttachmentMediaLog.tileLoad(
+                "load_exception",
+                "key" to decryptCacheKey,
+                "err" to (error.message ?: error::class.simpleName),
+                "msg" to AttachmentMediaLog.messageLabel(messageLabel),
+            )
+            null
+        } finally {
+            isAwaitingNetworkFull = false
+        }
+        cachedPath = uri
+        if (uri != null) {
+            fullBitmap = withContext(Dispatchers.Default) {
+                LocalDecodedImageCache.loadFull(decryptCacheKey, uri.removePrefix("file://"), target)
+            }
+        }
+        decryptFinished = true
+        AttachmentMediaLog.tileLoad(
+            if (fullBitmap != null) "load_done" else "load_failed",
+            "key" to decryptCacheKey,
+            "uri" to uri,
+            "msg" to AttachmentMediaLog.messageLabel(messageLabel),
+        )
+        if (fullBitmap != null) {
+            AttachmentDownloadNotifier.clearProgress(messageId, fileIndex, cacheClientId)
+            if (thumbBitmap == null) {
+                didRevealFull = true
+                fullRevealAlpha.snapTo(1f)
+                thumbBlurAlpha.snapTo(0f)
+            }
             onFullyLoaded(true)
         }
     }
 
+    LaunchedEffect(decryptCacheKey, tileDecodeSize) {
+        val target = tileDecodeSize ?: return@LaunchedEffect
+        val current = fullBitmap ?: return@LaunchedEffect
+        if (!LocalDecodedImageCache.needsUpscale(current, target)) return@LaunchedEffect
+        val path = cachedPath?.removePrefix("file://")
+            ?: localUri?.removePrefix("file://")
+            ?: DecryptedImageCache.getCached(messageId, fileIndex, cacheClientId)?.removePrefix("file://")
+            ?: return@LaunchedEffect
+        AttachmentMediaLog.tileLoad(
+            "upscale_start",
+            "key" to decryptCacheKey,
+            "from" to "${current.width}x${current.height}",
+            "target" to "${target.widthPx}x${target.heightPx}",
+        )
+        val upscaled = withContext(Dispatchers.Default) {
+            LocalDecodedImageCache.loadFull(decryptCacheKey, path, target)
+        }
+        if (upscaled != null) {
+            fullBitmap = upscaled
+            onFullyLoaded(true)
+        }
+    }
+
+    LaunchedEffect(fullBitmap, thumbBitmap, hadInstantFull) {
+        when {
+            fullBitmap == null -> {
+                didRevealFull = false
+                fullRevealAlpha.snapTo(0f)
+                if (thumbBitmap != null) thumbBlurAlpha.snapTo(1f)
+            }
+            didRevealFull -> return@LaunchedEffect
+            hadInstantFull -> {
+                didRevealFull = true
+                fullRevealAlpha.snapTo(1f)
+                thumbBlurAlpha.snapTo(0f)
+            }
+            thumbBitmap != null -> {
+                didRevealFull = true
+                thumbBlurAlpha.snapTo(1f)
+                fullRevealAlpha.snapTo(0f)
+                coroutineScope {
+                    launch {
+                        thumbBlurAlpha.animateTo(0f, tween(BLUR_FADE_MS, easing = FastOutSlowInEasing))
+                    }
+                    launch {
+                        fullRevealAlpha.animateTo(1f, tween(BLUR_FADE_MS, easing = FastOutSlowInEasing))
+                    }
+                }
+            }
+            else -> {
+                didRevealFull = true
+                fullRevealAlpha.snapTo(1f)
+                thumbBlurAlpha.snapTo(0f)
+            }
+        }
+    }
+
+    val isDownloadingFullImage = !isOutboundPending && fullBitmap == null &&
+        (downloadProgress != null || isAwaitingNetworkFull)
+    val showDownloadProgressOverlay = isDownloadingFullImage && !showOutboundBlurOverlay
+    val showLoadFailedOverlay = decryptFailed && fullBitmap == null && !isOutboundPending
+    val showSpinnerOnly = fullBitmap == null && thumbBitmap == null && !hasLocalSource &&
+        !showLoadFailedOverlay &&
+        !showOutboundBlurOverlay &&
+        (isDownloadingFullImage || (!decryptFinished && !isOutboundPending))
+
     Box(
         modifier = Modifier
             .fillMaxSize()
-            .clip(RoundedCornerShape(IMAGE_RADIUS))
-    ) {
-        Image(
-            painter = localPainter,
-            contentDescription = null,
-            modifier = Modifier.fillMaxSize(),
-            contentScale = ContentScale.Crop
-        )
-        AnimatedContent(
-            targetState = isUploading,
-            modifier = Modifier.matchParentSize(),
-            transitionSpec = {
-                (fadeIn(animationSpec = tween(220)) + scaleIn(initialScale = 0.98f, animationSpec = tween(220)))
-                    .togetherWith(
-                        fadeOut(animationSpec = tween(450, easing = FastOutSlowInEasing)) +
-                            scaleOut(targetScale = 1.02f, animationSpec = tween(450, easing = FastOutSlowInEasing))
-                    )
-            },
-            label = "upload_overlay"
-        ) { uploading ->
-            if (uploading) {
-                UploadingImageOverlay(
-                    model = localUri,
-                    uploadProgress = uploadProgress,
-                    modifier = Modifier.matchParentSize()
-                )
-            } else {
-                Box(modifier = Modifier.matchParentSize())
-            }
-        }
-        if (cachedPath != null && file != null) {
-            val fullPainter = rememberAsyncImagePainter(
-                model = cachedPath!!,
-                contentScale = ContentScale.FillWidth
-            )
-            val fullState by fullPainter.state.collectAsState()
-            when (fullState) {
-                is coil3.compose.AsyncImagePainter.State.Success -> {
-                    LaunchedEffect(Unit) { onFullyLoaded(true) }
-                    val alpha = remember { Animatable(0f) }
-                    LaunchedEffect(Unit) {
-                        alpha.animateTo(1f, animationSpec = tween(300))
+            .onGloballyPositioned { coordinates ->
+                val size: IntSize = coordinates.size
+                if (size.width > 0 && size.height > 0) {
+                    val measured = ChatPreviewDecodeSize(size.width, size.height)
+                    if (decodeSizeChangedMeaningfully(tileDecodeSize, measured)) {
+                        tileDecodeSize = measured
                     }
-                    Image(
-                        painter = fullPainter,
-                        contentDescription = file.name,
-                        modifier = Modifier
-                            .fillMaxSize()
-                            .alpha(alpha.value),
-                        contentScale = ContentScale.FillWidth
+                }
+            }
+            .clip(clipShape),
+    ) {
+        when {
+            else -> {
+                Box(
+                    modifier = Modifier
+                        .fillMaxSize()
+                        .background(tilePlaceholderColor),
+                )
+                if (fullBitmap == null && hasLocalSource && !showOutboundBlurOverlay) {
+                    AsyncImage(
+                        model = localUri,
+            contentDescription = null,
+                        contentScale = imageContentScale,
+            modifier = Modifier.fillMaxSize(),
+                    )
+                }
+                thumbBitmap?.let { thumb ->
+                    Box(
+                        modifier = Modifier
+                            .fillMaxSize()
+                            .then(
+                                if (thumbBlurAlpha.value > 0.01f) {
+                                    Modifier.hazeEffect(style = HazeMaterials.thin())
+                                } else {
+                                    Modifier
+                                },
+                            ),
+                    ) {
+                        CachedAttachmentImage(
+                            bitmap = thumb,
+                            contentDescription = serverFile?.name,
+                            contentScale = imageContentScale,
+                            modifier = Modifier
+                                .fillMaxSize()
+                                .alpha(thumbBlurAlpha.value.coerceIn(0f, 1f)),
+                        )
+                    }
+                }
+                fullBitmap?.let { full ->
+                    CachedAttachmentImage(
+                        bitmap = full,
+                        contentDescription = serverFile?.name,
+                        contentScale = imageContentScale,
+                        modifier = Modifier
+                            .fillMaxSize()
+                            .alpha(fullRevealAlpha.value.coerceIn(0f, 1f)),
+                    )
+                    LaunchedEffect(full) { onFullyLoaded(true) }
+                }
+                if (showDownloadProgressOverlay) {
+                    Box(
+                        modifier = Modifier
+                            .fillMaxSize()
+                            .background(MaterialTheme.colorScheme.scrim.copy(alpha = 0.12f)),
+                        contentAlignment = Alignment.Center,
+                    ) {
+                        ExpressiveUploadIndicator(
+                            uploadProgress = downloadProgress,
+                            modifier = Modifier.size(48.dp),
+                        )
+                    }
+                } else if (showSpinnerOnly) {
+                    Box(
+                        modifier = Modifier.fillMaxSize(),
+                        contentAlignment = Alignment.Center,
+                    ) {
+                        IndefiniteCircularProgress(modifier = Modifier.size(28.dp))
+                    }
+                }
+                if (showLoadFailedOverlay) {
+                    AttachmentImageLoadFailedOverlay(
+                        isAuthor = isAuthor,
+                        onRetry = {
+                            AttachmentDownloadNotifier.clearProgress(messageId, fileIndex, cacheClientId)
+                            decryptFinished = false
+                            ApiClient.clearPartialEncryptedDownload(decryptCacheKey)
+                            loadAttempt++
+                        },
+                        modifier = Modifier.matchParentSize(),
                     )
                 }
-                else -> Unit
             }
         }
+        if (showOutboundBlurOverlay && outboundOverlayAlpha.value > 0.01f) {
+            UploadingImageOverlay(
+                model = localUri!!,
+                uploadProgress = if (isUploading || awaitingServerAck) uploadProgress else null,
+                clipShape = clipShape,
+                contentScale = imageContentScale,
+                modifier = Modifier
+                    .matchParentSize()
+                    .alpha(outboundOverlayAlpha.value),
+            )
+        }
     }
 }
 
@@ -313,20 +680,22 @@ private fun UnifiedImageContent(
 private fun UploadingImageOverlay(
     model: String,
     uploadProgress: Int?,
-    modifier: Modifier = Modifier
+    clipShape: RoundedCornerShape,
+    contentScale: ContentScale = ContentScale.Fit,
+    modifier: Modifier = Modifier,
 ) {
     Box(modifier = modifier) {
         Box(
             modifier = Modifier
                 .matchParentSize()
-                .clip(RoundedCornerShape(IMAGE_RADIUS))
+                .clip(clipShape)
                 .hazeEffect(style = HazeMaterials.thin())
         ) {
             AsyncImage(
                 model = model,
                 contentDescription = null,
                 modifier = Modifier.fillMaxSize(),
-                contentScale = ContentScale.Crop
+                contentScale = contentScale,
             )
         }
         Box(
@@ -349,11 +718,16 @@ private fun ExpressiveUploadIndicator(
     uploadProgress: Int?,
     modifier: Modifier = Modifier,
     indicatorColor: Color? = null,
-    trackColorOverride: Color? = null
+    trackColorOverride: Color? = null,
 ) {
-    val clampedProgress = uploadProgress?.coerceIn(0, 100)
-    val indeterminate = clampedProgress == null || clampedProgress == 0
-    val waveActive = clampedProgress != null && clampedProgress in 1..99
+    // Latch first percent so we do not swap indeterminate ↔ determinate indicators (that resets animation).
+    var latchedPercent by remember { mutableStateOf<Int?>(null) }
+    if (uploadProgress != null) {
+        latchedPercent = uploadProgress.coerceIn(0, 100)
+    }
+    val clampedProgress = latchedPercent
+    val indeterminate = clampedProgress == null
+    val waveActive = clampedProgress != null && clampedProgress < 100
 
     val waveAnimSpec = tween<Float>(durationMillis = 320, easing = FastOutSlowInEasing)
 
@@ -406,7 +780,7 @@ private fun PendingImageContent(
         Box(
             modifier = Modifier
                 .fillMaxSize()
-                .clip(RoundedCornerShape(IMAGE_RADIUS))
+                .clip(attachmentImageCornerShape(isAuthor = false))
         ) {
             AsyncImage(
                 model = uri,
@@ -430,7 +804,8 @@ private fun PendingImageContent(
                     UploadingImageOverlay(
                         model = uri,
                         uploadProgress = uploadProgress,
-                        modifier = Modifier.matchParentSize()
+                        clipShape = attachmentImageCornerShape(isAuthor = false),
+                        modifier = Modifier.matchParentSize(),
                     )
                 } else {
                     Box(modifier = Modifier.matchParentSize())
@@ -491,153 +866,88 @@ private fun DeterminateCircularProgress(
     )
 }
 
-@OptIn(ExperimentalHazeMaterialsApi::class)
 @Composable
-private fun DecryptedImageContent(
-    messageId: Int,
-    fileIndex: Int,
-    file: DmFile,
-    envelope: DmEnvelope,
-    currentUserId: Int?,
-    thumbnailBase64: String,
-    aspectRatio: Float?,
-    onFullyLoaded: (Boolean) -> Unit = {}
+internal fun CachedAttachmentImage(
+    bitmap: ImageBitmap,
+    contentDescription: String?,
+    contentScale: ContentScale,
+    modifier: Modifier = Modifier.fillMaxSize(),
 ) {
-    var cachedPath by remember(messageId, fileIndex, file.path) {
-        mutableStateOf(DecryptedImageCache.getCached(messageId, fileIndex, file.path))
-    }
-    val thumbnailBytes = remember(thumbnailBase64) {
-        runCatching { Base64.decode(thumbnailBase64) }.getOrNull()
-    }
+    Image(
+        bitmap = bitmap,
+        contentDescription = contentDescription,
+        modifier = modifier,
+        contentScale = contentScale,
+    )
+}
 
-    LaunchedEffect(messageId, fileIndex, file.path, envelope) {
-        cachedPath = DecryptedImageCache.getOrDecrypt(messageId, fileIndex, file, envelope, currentUserId)
-    }
+@Composable
+internal fun FullscreenBitmapImage(
+    bitmap: ImageBitmap,
+    contentDescription: String?,
+    contentScale: ContentScale,
+    modifier: Modifier = Modifier.fillMaxSize(),
+) = CachedAttachmentImage(bitmap, contentDescription, contentScale, modifier)
 
+/** Supports raw base64 and `data:*;base64,` payloads from the server. */
+internal fun decodeAttachmentThumbnailBase64(value: String): ByteArray? {
+    val payload = value.trim().substringAfter("base64,", value).trim()
+    if (payload.isEmpty()) return null
+    return runCatching { Base64.decode(payload) }.getOrNull()
+}
+
+@Composable
+private fun AttachmentImageLoadFailedOverlay(
+    isAuthor: Boolean,
+    onRetry: () -> Unit,
+    modifier: Modifier = Modifier,
+) {
+    val failedText = stringResource(Res.string.attachment_image_load_failed)
+    val retryText = stringResource(Res.string.attachment_retry)
+    val retryCd = stringResource(Res.string.cd_attachment_retry)
+    val headlineColor = if (isAuthor) Color.White else MaterialTheme.colorScheme.onSurface
     Box(
-        modifier = Modifier
-            .fillMaxSize()
-            .clip(RoundedCornerShape(IMAGE_RADIUS))
+        modifier = modifier
+            .background(MaterialTheme.colorScheme.scrim.copy(alpha = 0.35f)),
+        contentAlignment = Alignment.Center,
     ) {
-        Box(modifier = Modifier.fillMaxSize()) {
-        when {
-            cachedPath != null -> {
-                val fullPainter = rememberAsyncImagePainter(
-                    model = cachedPath!!,
-                    contentScale = ContentScale.FillWidth
-                )
-                val fullState by fullPainter.state.collectAsState()
-                when (fullState) {
-                    is coil3.compose.AsyncImagePainter.State.Success -> {
-                        LaunchedEffect(Unit) { onFullyLoaded(true) }
-                        Image(
-                            painter = fullPainter,
-                            contentDescription = file.name,
-                            modifier = Modifier.fillMaxSize(),
-                            contentScale = ContentScale.FillWidth
-                        )
-                    }
-                    is coil3.compose.AsyncImagePainter.State.Loading -> {
-                        Box(
-                            modifier = Modifier.fillMaxSize(),
-                            contentAlignment = Alignment.Center
-                        ) {
-                            IndefiniteCircularProgress(modifier = Modifier.size(32.dp))
-                        }
-                    }
-                    else -> {
-                        Box(
-                            modifier = Modifier.fillMaxSize(),
-                            contentAlignment = Alignment.Center
-                        ) {
-                            IndefiniteCircularProgress(modifier = Modifier.size(32.dp))
-                        }
-                    }
-                }
-            }
-            thumbnailBytes == null -> {
-                Box(
-                    modifier = Modifier.fillMaxSize(),
-                    contentAlignment = Alignment.Center
-                ) {
-                    IndefiniteCircularProgress(modifier = Modifier.size(32.dp))
-                }
-            }
-            else -> {
-                val thumbPainter = rememberAsyncImagePainter(
-                    model = thumbnailBytes,
-                    contentScale = ContentScale.Crop
-                )
-                val thumbState by thumbPainter.state.collectAsState()
-                when (thumbState) {
-                    is coil3.compose.AsyncImagePainter.State.Loading -> {
-                        Box(
-                            modifier = Modifier.fillMaxSize(),
-                            contentAlignment = Alignment.Center
-                        ) {
-                            IndefiniteCircularProgress(modifier = Modifier.size(32.dp))
-                        }
-                    }
-                    is coil3.compose.AsyncImagePainter.State.Success -> {
-                        LaunchedEffect(Unit) { onFullyLoaded(true) }
-                        Box(
-                            modifier = Modifier
-                                .fillMaxSize()
-                                .clip(RoundedCornerShape(IMAGE_RADIUS))
-                                .hazeEffect(style = HazeMaterials.thin())
-                        ) {
-                            Image(
-                                painter = thumbPainter,
-                                contentDescription = file.name,
-                                modifier = Modifier.fillMaxSize(),
-                                contentScale = ContentScale.Crop
-                            )
-                        }
-                        if (cachedPath != null) {
-                            val fullPainter = rememberAsyncImagePainter(
-                                model = cachedPath!!,
-                                contentScale = ContentScale.FillWidth
-                            )
-                            val fullState by fullPainter.state.collectAsState()
-                            when (fullState) {
-                                is coil3.compose.AsyncImagePainter.State.Success -> {
-                                    LaunchedEffect(Unit) { onFullyLoaded(true) }
-                                    val alpha = remember { Animatable(0f) }
-                                    LaunchedEffect(Unit) {
-                                        alpha.animateTo(1f, animationSpec = tween(300))
-                                    }
-                                    Image(
-                                        painter = fullPainter,
-                                        contentDescription = file.name,
-                                        modifier = Modifier
-                                            .fillMaxSize()
-                                            .alpha(alpha.value),
-                                        contentScale = ContentScale.FillWidth
-                                    )
-                                }
-                                else -> {
-                                    Box(
-                                        modifier = Modifier.fillMaxSize(),
-                                        contentAlignment = Alignment.Center
-                                    ) {
-                                        IndefiniteCircularProgress(modifier = Modifier.size(32.dp))
-                                    }
-                                }
-                            }
-                        }
-                    }
-                    else -> {
-                        Box(
-                            modifier = Modifier.fillMaxSize(),
-                            contentAlignment = Alignment.Center
-                        ) {
-                            IndefiniteCircularProgress(modifier = Modifier.size(32.dp))
-                        }
-                    }
-                }
+        Column(
+            horizontalAlignment = Alignment.CenterHorizontally,
+            verticalArrangement = Arrangement.spacedBy(6.dp),
+            modifier = Modifier.padding(horizontal = 12.dp),
+        ) {
+            Text(
+                text = failedText,
+                style = MaterialTheme.typography.bodySmall,
+                color = headlineColor,
+            )
+            TextButton(
+                onClick = onRetry,
+                modifier = Modifier.semantics { contentDescription = retryCd },
+            ) {
+                Text(text = retryText, color = headlineColor)
             }
         }
-        }
+    }
+}
+
+@Composable
+private fun CorruptedImagePlaceholder(
+    modifier: Modifier = Modifier,
+    clipShape: RoundedCornerShape = attachmentImageCornerShape(isAuthor = false),
+) {
+    Box(
+        modifier = modifier
+            .clip(clipShape)
+            .hazeEffect(style = HazeMaterials.thin()),
+        contentAlignment = Alignment.Center,
+    ) {
+        Icon(
+            imageVector = Icons.Rounded.AttachFile,
+            contentDescription = null,
+            modifier = Modifier.size(32.dp),
+            tint = MaterialTheme.colorScheme.onSurfaceVariant,
+        )
     }
 }
 

app/shared/src/commonMain/kotlin/ru/fromchat/ui/chat/ChatPanel.kt

@@ -8,9 +8,15 @@ import kotlinx.coroutines.launch
 import kotlinx.coroutines.sync.Mutex
 import kotlinx.coroutines.sync.withLock
 import kotlinx.serialization.Serializable
+import ru.fromchat.api.ApiClient
 import ru.fromchat.api.Message
+import ru.fromchat.api.generateClientMessageId
+import ru.fromchat.api.nowMessageTimestampIso
+import ru.fromchat.api.sortMessagesForChatDisplay
 import ru.fromchat.api.WebSocketMessage
 import ru.fromchat.core.Logger
+import ru.fromchat.ui.chat.dedupeMessagesByClientId
+import ru.fromchat.ui.chat.dropSupersededOptimisticMessages
 import kotlin.time.Clock
 import kotlin.time.ExperimentalTime
 
@@ -70,6 +76,17 @@ abstract class ChatPanel(
      */
     fun getState(): ChatPanelState = _state.copy()
 
+    /** Merge SQLDelight rows with in-memory optimistic attachment UI (pending preview, thumbnails). */
+    suspend fun syncMessagesFromDatabase(messages: List<Message>) {
+        batchStateUpdates {
+            updateState { current ->
+                val merged = mergeDatabaseMessagesWithPanelState(current.messages, messages)
+                if (current.messages == merged) current
+                else current.copy(messages = merged)
+            }
+        }
+    }
+
     /**
      * Update state
      */
@@ -103,9 +120,9 @@ abstract class ChatPanel(
             batchDepth--
             if (batchDepth == 0) {
                 val callback = onStateChange
-                val stateToSend = pendingBatchedState
                 pendingBatchedState = null
-                if (callback != null && stateToSend != null) {
+                val stateToSend = _state.copy()
+                if (callback != null) {
                     scope.launch(Dispatchers.Main) {
                         Logger.d(
                             "ChatPanel",
@@ -142,7 +159,7 @@ abstract class ChatPanel(
             if (!messageExists) {
                 Logger.d("ChatPanel", "Adding message: id=${message.id}, content=${message.content.take(50)}")
                 updateState { currentState ->
-                    val newMessages = currentState.messages + message
+                    val newMessages = sortMessagesForChatDisplay(currentState.messages + message)
                     Logger.d("ChatPanel", "Messages count after add: ${newMessages.size}")
                     currentState.copy(messages = newMessages)
                 }
@@ -170,7 +187,11 @@ abstract class ChatPanel(
             }
             if (newOnes.isNotEmpty()) {
                 updateState { currentState ->
-                    val newMessages = (currentState.messages + newOnes).sortedBy { it.timestamp }
+                    val merged = dropSupersededOptimisticMessages(
+                        currentState.messages + newOnes,
+                        ApiClient.user?.id,
+                    )
+                    val newMessages = sortMessagesForChatDisplay(dedupeMessagesByClientId(merged))
                     currentState.copy(messages = newMessages)
                 }
             }
@@ -194,6 +215,40 @@ abstract class ChatPanel(
         }
     }
 
+    fun updateMessageByClientMessageId(clientMessageId: String, updates: (Message) -> Message) {
+        val cid = clientMessageId.trim()
+        if (cid.isEmpty()) return
+        updateState { currentState ->
+            currentState.copy(
+                messages = currentState.messages.map { msg ->
+                    if (msg.client_message_id == cid || msg.uploadJobId == cid) updates(msg) else msg
+                },
+            )
+        }
+    }
+
+    /** Conversation id used for outbox / local DB (DM peer or public group). */
+    abstract fun outboxConversationId(): String
+
+    open suspend fun cancelQueuedMessage(message: Message) {
+        val cid = message.client_message_id?.trim().orEmpty()
+        if (cid.isEmpty()) return
+        if (message.pendingFileUri != null) {
+            clearOutboundImageCaches(cid, message.id)
+        }
+        removeMessage(message.id)
+        ru.fromchat.api.outbox.OutgoingMessageCoordinator.cancelOutboundMessage(cid, outboxConversationId())
+    }
+
+    suspend fun cancelQueuedMessageByClientId(clientMessageId: String) {
+        val cid = clientMessageId.trim()
+        if (cid.isEmpty()) return
+        val message = _state.messages.find { msg ->
+            msg.client_message_id == cid || msg.uploadJobId == cid
+        } ?: return
+        cancelQueuedMessage(message)
+    }
+
     /**
      * Remove message from list
      */
@@ -214,6 +269,23 @@ abstract class ChatPanel(
         updateState { it.copy(messages = emptyList()) }
     }
 
+    /** In-flight sends only (active [pendingMessages]), not stale cache optimistics. */
+    protected fun snapshotPendingOptimisticMessages(): List<Message> {
+        if (pendingMessages.isEmpty()) return emptyList()
+        val pendingClientIds = pendingMessages.keys
+        return _state.messages.filter { msg ->
+            val cid = msg.client_message_id?.trim().orEmpty()
+            cid.isNotEmpty() && cid in pendingClientIds
+        }
+    }
+
+    protected suspend fun restorePendingOptimisticMessages(messages: List<Message>) {
+        if (messages.isEmpty()) return
+        val filtered = dropSupersededOptimisticMessages(messages, ApiClient.user?.id)
+        if (filtered.isEmpty()) return
+        addMessages(filtered)
+    }
+
     /**
      * Set loading state
      */
@@ -258,7 +330,7 @@ abstract class ChatPanel(
                     mapped + confirmedMessage
                 else -> mapped
             }
-            currentState.copy(messages = messages)
+            currentState.copy(messages = sortMessagesForChatDisplay(messages))
         }
         scope.launch(Dispatchers.Default) {
             runCatching { onOptimisticMessageConfirmed(tempId, confirmedMessage) }
@@ -274,7 +346,7 @@ abstract class ChatPanel(
     suspend fun retryMessage(messageId: Int) {
         val message = _state.messages.find { it.id == messageId } ?: return
 
-        val tempId = "temp_${Clock.System.now().toEpochMilliseconds()}_${(0..999999).random()}"
+        val tempId = generateClientMessageId()
         val newOptimistic = message.copy(
             id = uniqueOptimisticMessageId(),
             client_message_id = tempId
@@ -334,12 +406,12 @@ abstract class ChatPanel(
         if (content.isBlank()) return
 
         // Create temporary message for immediate display
-        val tempId = "temp_${Clock.System.now().toEpochMilliseconds()}_${(0..999999).random()}"
+        val tempId = generateClientMessageId()
         val tempMessage = Message(
             id = -1, // Temporary negative ID
             user_id = currentUserId ?: -1,
             content = content.trim(),
-            timestamp = Clock.System.now().toString(),
+            timestamp = nowMessageTimestampIso(),
             is_read = false,
             is_edited = false,
             username = "You",
@@ -391,6 +463,9 @@ abstract class ChatPanel(
     /** Persist optimistic row for offline / process death; no-op by default. */
     protected open suspend fun persistOptimisticMessage(message: Message) {}
 
+    /** Persists an outbound row to the local DB (DM/public overrides). */
+    suspend fun persistOutboundMessage(message: Message) = persistOptimisticMessage(message)
+
     protected open suspend fun removeOptimisticFromCache(message: Message) {}
 
     /**

app/shared/src/commonMain/kotlin/ru/fromchat/ui/chat/ChatScreen.kt

@@ -34,6 +34,7 @@ import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.runtime.setValue
+import androidx.compose.runtime.snapshotFlow
 import androidx.compose.runtime.withFrameNanos
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
@@ -48,16 +49,24 @@ import dev.chrisbanes.haze.hazeSource
 import dev.chrisbanes.haze.materials.ExperimentalHazeMaterialsApi
 import dev.chrisbanes.haze.materials.HazeMaterials
 import dev.chrisbanes.haze.rememberHazeState
+import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.delay
+import kotlinx.coroutines.flow.distinctUntilChanged
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 import kotlinx.serialization.json.decodeFromJsonElement
 import kotlinx.serialization.json.jsonObject
 import kotlinx.serialization.json.jsonPrimitive
 import org.jetbrains.compose.resources.stringResource
 import ru.fromchat.Res
 import ru.fromchat.api.ApiClient
-import ru.fromchat.api.AttachmentUploadJob
-import ru.fromchat.api.AttachmentUploadQueue
+import ru.fromchat.api.AttachmentUploadNotifier
+import ru.fromchat.api.AttachmentUploadProgress
+import ru.fromchat.api.generateClientMessageId
+import ru.fromchat.api.nowMessageTimestampIso
+import ru.fromchat.api.optimisticMessageIdForClientMessageId
+import ru.fromchat.api.outbox.OutgoingMessageCoordinator
+import com.pr0gramm3r101.utils.supportClipboardManagerImpl
 import ru.fromchat.api.ConnectionStateStore
 import ru.fromchat.api.ConnectionStatus
 import ru.fromchat.api.Message
@@ -220,7 +229,26 @@ fun ChatScreen(
     var expandedImage by remember { mutableStateOf<Pair<Message, Int>?>(null) }
     var isImageClosing by remember { mutableStateOf(false) }
     val imageThumbBounds = remember { mutableStateMapOf<String, Rect>() }
-    val expandedImageKey = expandedImage?.let { (msg, idx) -> "img_${msg.id}_$idx" }
+    val expandedImageKey = expandedImage?.let { (msg, idx) ->
+        val cid = msg.client_message_id?.trim().orEmpty()
+        if (cid.isNotEmpty()) "img_${cid}_$idx" else "img_${msg.id}_$idx"
+    }
+
+    LaunchedEffect(listState, panelState.messages, expandedImage) {
+        try {
+            snapshotFlow {
+                visibleMessageIdsInChatList(
+                    listState = listState,
+                    messages = panelState.messages,
+                    extraMessageId = expandedImage?.first?.id,
+                )
+            }
+                .distinctUntilChanged()
+                .collect { ids -> AttachmentDownloadVisibility.setVisibleMessageIds(ids) }
+        } finally {
+            AttachmentDownloadVisibility.setVisibleMessageIds(emptySet())
+        }
+    }
 
     // Collect WebSocket messages
     LaunchedEffect(Unit) {
@@ -311,11 +339,27 @@ fun ChatScreen(
     var didInitialScroll by rememberSaveable(panelId) { mutableStateOf(false) }
     // LaunchedEffect restarts when returning from profile even if message keys are unchanged; skip auto-scroll unless the list actually changed.
     var previousMessageFingerprint by rememberSaveable(panelId) { mutableStateOf("") }
-    LaunchedEffect(panelState.messages.size, panelState.messages.lastOrNull()?.id, panelState.messages.lastOrNull()?.pendingFileAspectRatio) {
+    var previousMessageCount by rememberSaveable(panelId) { mutableStateOf(-1) }
+    LaunchedEffect(
+        panelState.messages.size,
+        panelState.messages.lastOrNull()?.client_message_id,
+        panelState.messages.lastOrNull()?.uploadProgress,
+        panelState.messages.lastOrNull()?.pendingFileAspectRatio,
+    ) {
         if (panelState.messages.isEmpty()) return@LaunchedEffect
 
+        val newCount = panelState.messages.size
+        if (previousMessageCount >= 0 && newCount < previousMessageCount) {
+            previousMessageCount = newCount
+            val lastMessage = panelState.messages.lastOrNull()
+            previousMessageFingerprint =
+                "${newCount}|${lastMessage?.client_message_id}|${lastMessage?.uploadProgress}|${lastMessage?.pendingFileAspectRatio}"
+            return@LaunchedEffect
+        }
+        previousMessageCount = newCount
+
         val lastMessage = panelState.messages.lastOrNull()
-        val fingerprint = "${panelState.messages.size}|${lastMessage?.id}|${lastMessage?.pendingFileAspectRatio}"
+        val fingerprint = "${newCount}|${lastMessage?.client_message_id}|${lastMessage?.uploadProgress}|${lastMessage?.pendingFileAspectRatio}"
 
         if (!didInitialScroll) {
             didInitialScroll = true
@@ -341,19 +385,50 @@ fun ChatScreen(
         }
     }
 
+    val clipboard = supportClipboardManagerImpl
+
+    LaunchedEffect(contextMenuState.isOpen, contextMenuState.message, panelState.messages, currentUserId, isReadOnly) {
+        if (!contextMenuState.isOpen) return@LaunchedEffect
+        val menuMessage = contextMenuState.message ?: return@LaunchedEffect
+        val cid = menuMessage.client_message_id?.trim().orEmpty()
+        val liveMessage = panelState.messages.find { msg ->
+            if (cid.isNotEmpty()) {
+                msg.client_message_id?.trim() == cid
+            } else {
+                msg.id == menuMessage.id
+            }
+        }
+        if (liveMessage == null) {
+            contextMenuState = contextMenuState.copy(isOpen = false, message = null)
+            return@LaunchedEffect
+        }
+        val menuAuthor = menuMessage.user_id == currentUserId
+        val liveAuthor = liveMessage.user_id == currentUserId
+        val menuFp = messageContextMenuFingerprint(menuMessage, menuAuthor, isReadOnly)
+        val liveFp = messageContextMenuFingerprint(liveMessage, liveAuthor, isReadOnly)
+        if (menuFp != liveFp) {
+            contextMenuState = contextMenuState.copy(isOpen = false, message = null)
+        }
+    }
+
     LaunchedEffect(panel) {
         if (panel.getRecipientId() != null) {
-            AttachmentUploadQueue.progressFlow.collect { progress ->
+            AttachmentUploadNotifier.progressFlow.collect { progress ->
                 when (progress) {
-                    is ru.fromchat.api.AttachmentUploadProgress.InProgress ->
-                        panel.updateMessage(-progress.jobId.hashCode().let { if (it == 0) -1 else it }) {
-                            if (it.uploadJobId == progress.jobId) it.copy(uploadProgress = progress.percent) else it
+                    is AttachmentUploadProgress.InProgress ->
+                        panel.updateMessageByClientMessageId(progress.jobId) {
+                            it.copy(uploadProgress = progress.percent)
                         }
-                    is ru.fromchat.api.AttachmentUploadProgress.Success ->
-                        panel.updateMessage(-progress.jobId.hashCode().let { if (it == 0) -1 else it }) {
-                            if (it.uploadJobId == progress.jobId) it.copy(uploadProgress = null) else it
+                    is AttachmentUploadProgress.Success ->
+                        panel.updateMessageByClientMessageId(progress.jobId) {
+                            it.copy(uploadProgress = null)
                         }
-                    else -> {}
+                    is AttachmentUploadProgress.Failed -> {
+                        if (progress.error != "Cancelled") {
+                            scope.launch { panel.cancelQueuedMessageByClientId(progress.jobId) }
+                        }
+                    }
+                    else -> Unit
                 }
             }
         }
@@ -401,51 +476,75 @@ fun ChatScreen(
                                     if (attachments.isNotEmpty() && recipientId != null) {
                                         val plaintext = text.ifBlank { "" }
                                         attachments.forEach { att ->
-                                            val jobId = "dm_${Clock.System.now().toEpochMilliseconds()}_${att.id}"
-                                            val hc = jobId.hashCode()
-                                            val absHc = if (hc == Int.MIN_VALUE) Int.MAX_VALUE else kotlin.math.abs(hc)
-                                            val tempId = -(absHc.let { if (it == 0) 1 else it })
+                                            val jobId = generateClientMessageId()
+                                            val tempId = optimisticMessageIdForClientMessageId(jobId)
                                             val isImage = att.isImage
-                                            val optimisticMessage = Message(
-                                                id = tempId,
-                                                user_id = currentUserId ?: -1,
-                                                content = plaintext.ifBlank { att.filename },
-                                                timestamp = Clock.System.now().toString(),
-                                                is_read = false,
-                                                is_edited = false,
-                                                username = "You",
-                                                profile_picture = null,
-                                                verified = null,
-                                                reply_to = replyTo,
-                                                client_message_id = jobId,
-                                                reactions = null,
-                                                files = null,
-                                                pendingFileUri = att.uri,
-                                                pendingFilename = att.filename,
-                                                uploadJobId = jobId,
-                                                uploadProgress = 0
-                                            )
-                                            panel.addMessage(optimisticMessage)
-                                            if (isImage) {
-                                                scope.launch {
-                                                    val aspectRatio = getImageAspectRatio(att.uri)
-                                                    if (aspectRatio != null && aspectRatio > 0f) {
-                                                        panel.updateMessage(tempId) {
-                                                            if (it.uploadJobId == jobId) it.copy(pendingFileAspectRatio = aspectRatio) else it
-                                                        }
-                                                    }
+                                            scope.launch(Dispatchers.Default) {
+                                                val imageDimensions = if (isImage) {
+                                                    getImageDimensions(att.uri)
+                                                } else {
+                                                    null
                                                 }
-                                            }
-                                            AttachmentUploadQueue.enqueue(
-                                                AttachmentUploadJob(
-                                                    jobId = jobId,
-                                                    fileUri = att.uri,
-                                                    filename = att.filename,
+                                                val aspectRatio = imageDimensions?.let { (w, h) ->
+                                                    if (h > 0) w.toFloat() / h.toFloat() else null
+                                                }?.takeIf { it > 0f }
+                                                    ?: if (isImage) {
+                                                        getImageAspectRatio(att.uri)?.takeIf { it > 0f }
+                                                    } else {
+                                                        null
+                                                    }
+                                                val staged = if (isImage) {
+                                                    prepareOutboundImageForSend(
+                                                        clientMessageId = jobId,
+                                                        sourceUri = att.uri,
+                                                        optimisticMessageId = tempId,
+                                                        aspectRatio = aspectRatio,
+                                                    )
+                                                } else {
+                                                    null
+                                                }
+                                                val fileUri = staged?.stagedUri ?: att.uri
+                                                val optimisticMessage = Message(
+                                                    id = tempId,
+                                                    user_id = currentUserId ?: -1,
+                                                    content = plaintext.ifBlank { att.filename },
+                                                    timestamp = nowMessageTimestampIso(),
+                                                    is_read = false,
+                                                    is_edited = false,
+                                                    username = "You",
+                                                    profile_picture = null,
+                                                    verified = null,
+                                                    reply_to = replyTo,
+                                                    client_message_id = jobId,
+                                                    reactions = null,
+                                                    files = null,
+                                                    pendingFileUri = fileUri,
+                                                    pendingFilename = att.filename,
+                                                    uploadJobId = jobId,
+                                                    uploadProgress = if (isImage) 0 else null,
+                                                    pendingFileAspectRatio = staged?.aspectRatio ?: aspectRatio,
+                                                    fileDimensions = imageDimensions?.let { listOf(it) },
+                                                )
+                                                withContext(Dispatchers.Main) {
+                                                    panel.addMessage(optimisticMessage)
+                                                }
+                                                if (isImage && staged == null) {
+                                                    withContext(Dispatchers.Main) {
+                                                        panel.cancelQueuedMessageByClientId(jobId)
+                                                    }
+                                                    return@launch
+                                                }
+                                                OutgoingMessageCoordinator.enqueueDmAttachment(
                                                     recipientId = recipientId,
                                                     plaintext = plaintext.ifBlank { att.filename },
-                                                    replyToId = replyToId
+                                                    clientMessageId = jobId,
+                                                    replyToId = replyToId,
+                                                    fileUri = fileUri,
+                                                    filename = att.filename,
+                                                    optimisticMessage = optimisticMessage,
+                                                    aspectRatio = staged?.aspectRatio ?: aspectRatio,
                                                 )
-                                            )
+                                            }
                                         }
                                     } else if (text.isNotBlank()) {
                                         panel.sendMessageWithImmediateDisplay(text, replyToId)
@@ -516,7 +615,8 @@ fun ChatScreen(
                         items(
                             items = panelState.messages.asReversed(),
                             key = { msg ->
-                                msg.client_message_id ?: "id_${msg.id}_${msg.timestamp}"
+                                val cid = msg.client_message_id?.trim().orEmpty()
+                                if (cid.isNotEmpty()) "c:$cid" else "i:${msg.id}:${msg.timestamp}"
                             }
                         ) { message ->
                             var tapPositionInRoot by remember { mutableStateOf(IntOffset(0, 0)) }
@@ -650,13 +750,23 @@ fun ChatScreen(
                                 panel.handleDeleteMessage(message.id)
                             }
                         },
+                        onCopy = { message ->
+                            if (message.isContentCorrupted) return@MessageContextMenu
+                            val text = message.content.trim()
+                            if (text.isNotEmpty()) {
+                                scope.launch { clipboard.setText(text) }
+                            }
+                        },
+                        onCancelSend = { message ->
+                            scope.launch { panel.cancelQueuedMessage(message) }
+                        },
                     )
                 }
             }
         }
 
         expandedImage?.let { (msg, idx) ->
-            val key = "img_${msg.id}_$idx"
+            val key = imageAttachmentKey(msg, idx)
             ImageFullscreenPreview(
                 message = msg,
                 fileIndex = idx,

app/shared/src/commonMain/kotlin/ru/fromchat/ui/chat/DecryptedImageCache.kt

@@ -2,85 +2,458 @@ package ru.fromchat.ui.chat
 
 import com.pr0gramm3r101.utils.files.PlatformFileSystem
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.NonCancellable
 import kotlinx.coroutines.sync.Mutex
 import kotlinx.coroutines.sync.withLock
 import kotlinx.coroutines.withContext
+import ru.fromchat.api.ApiClient
 import ru.fromchat.api.DmEnvelope
 import ru.fromchat.api.DmFile
+import ru.fromchat.api.AttachmentDownloadNotifier
+import ru.fromchat.api.AttachmentDownloadProgress
 import ru.fromchat.crypto.decryptFile
 
 /**
- * Disk cache for decrypted image bytes. Key includes messageId, fileIndex, and file.path
- * so that server updates (e.g. image replacement) produce cache misses via path change.
+ * Disk + in-memory cache for decrypted DM images.
+ * Key is stable per attachment slot ([client_message_id] + index, or [messageId] + index).
  */
 object DecryptedImageCache {
+    private const val SUBDIR = "decrypted_images"
+
+    /** True when [uri] points at a file under this cache (safe to persist for offline preview). */
+    fun isDecryptedImageCacheUri(uri: String?): Boolean {
+        if (uri.isNullOrBlank()) return false
+        val path = uri.removePrefix("file://")
+        return path.contains("/$SUBDIR/") || path.endsWith("/$SUBDIR")
+    }
+
     private var cacheDir: String? = null
-    private val mutex = Mutex()
+    private val cacheMutex = Mutex()
+    private val memoryCache = mutableMapOf<String, String>()
 
     fun init(cacheDirPath: String) {
         cacheDir = cacheDirPath
     }
 
-    private fun ensureCacheDir(): String? {
-        if (cacheDir == null) {
-            val base = PlatformFileSystem.getAppCacheDirectory()
-            if (base.isEmpty()) return null
-            cacheDir = PlatformFileSystem.ensureDirectory("$base/decrypted_images")
+    /**
+     * Stable identity for one attachment slot. Does not include [filePath] so confirm/scroll
+     * cannot miss cache when the server path string varies; edits/deletes invalidate explicitly.
+     */
+    fun storageKey(
+        messageId: Int,
+        fileIndex: Int,
+        clientMessageId: String? = null,
+    ): String {
+        if (messageId > 0) {
+            return "img_${messageId}_$fileIndex"
+        }
+        val cid = clientMessageId?.trim()?.takeIf { it.isNotEmpty() }
+        return if (cid != null) {
+            "img_c_${sanitizeKeyPart(cid)}_$fileIndex"
+        } else {
+            "img_${messageId}_$fileIndex"
         }
-        return cacheDir
     }
 
-    private fun key(messageId: Int, fileIndex: Int, filePath: String): String {
-        val safePath = filePath.hashCode().toString(36).replace("-", "m")
-        return "img_${messageId}_${fileIndex}_$safePath"
+    /** Keys that may refer to the same slot (progress UI + cache aliases). */
+    fun progressLookupKeys(
+        messageId: Int,
+        fileIndex: Int,
+        clientMessageId: String? = null,
+    ): List<String> = buildList {
+        add(storageKey(messageId, fileIndex, clientMessageId))
+        if (messageId > 0) add("img_${messageId}_$fileIndex")
+        val cid = clientMessageId?.trim()?.takeIf { it.isNotEmpty() }
+        if (cid != null) add("img_c_${sanitizeKeyPart(cid)}_$fileIndex")
+    }.distinct()
+
+    fun resolveDownloadPercent(
+        messageId: Int,
+        fileIndex: Int,
+        clientMessageId: String? = null,
+        progressByKey: Map<String, Int> = emptyMap(),
+    ): Int? {
+        for (lookupKey in progressLookupKeys(messageId, fileIndex, clientMessageId)) {
+            progressByKey[lookupKey]?.let { return it }
+        }
+        return null
     }
 
-    fun getCached(messageId: Int, fileIndex: Int, filePath: String): String? {
-        val dir = ensureCacheDir() ?: return null
-        val path = "$dir/${key(messageId, fileIndex, filePath)}"
-        return if (PlatformFileSystem.exists(path)) "file://$path" else null
+    /** Synchronous disk lookup (safe to call from the main thread during composition). */
+    fun getCached(
+        messageId: Int,
+        fileIndex: Int,
+        clientMessageId: String? = null,
+    ): String? {
+        val cid = clientMessageId?.trim()?.takeIf { it.isNotEmpty() }
+        if (cid != null) {
+            readDisk(storageKey(messageId, fileIndex, cid))?.let { return it }
+        }
+        return readDisk(storageKey(messageId, fileIndex, null))
     }
 
+    fun getUriForStorageKey(storageKey: String): String? = readDisk(storageKey)
+
+    fun messageIdFromStorageKey(storageKey: String): Int? {
+        if (!storageKey.startsWith("img_") || storageKey.startsWith("img_c_")) return null
+        return storageKey.removePrefix("img_").substringBefore('_').toIntOrNull()
+    }
+
+    /** After confirm, cache file may only exist under client-id key; copy to message-id key for reopen. */
+    suspend fun ensureDiskAliasForMessageId(
+        messageId: Int,
+        fileIndex: Int,
+        clientMessageId: String?,
+    ) {
+        if (messageId <= 0) return
+        val idKey = storageKey(messageId, fileIndex, null)
+        if (readDisk(idKey) != null) return
+        val cid = clientMessageId?.trim()?.takeIf { it.isNotEmpty() } ?: return
+        val cidKey = storageKey(messageId, fileIndex, cid)
+        val sourceUri = readDisk(cidKey) ?: return
+        val bytes = runCatching {
+            ru.fromchat.core.cache.readOutboundFileBytes(sourceUri)
+        }.getOrNull() ?: return
+        if (bytes.isEmpty()) return
+        withContext(Dispatchers.Default + NonCancellable) {
+            cacheMutex.withLock {
+                if (readDisk(idKey) == null) {
+                    writeCacheLocked(idKey, bytes)
+                    AttachmentMediaLog.diskCache(
+                        "alias_ok",
+                        "from" to cidKey,
+                        "to" to idKey,
+                        "bytes" to bytes.size,
+                    )
+                }
+            }
+        }
+    }
+
+    /**
+     * Returns a cached file URI, decrypting and persisting once per [storageKey].
+     */
     suspend fun getOrDecrypt(
         messageId: Int,
         fileIndex: Int,
         file: DmFile,
         envelope: DmEnvelope?,
-        currentUserId: Int?
+        currentUserId: Int?,
+        clientMessageId: String? = null,
+        messageLabel: String? = null,
     ): String? {
         if (envelope == null) return null
-        val dir = ensureCacheDir() ?: return null
-        val k = key(messageId, fileIndex, file.path)
-        val path = "$dir/$k"
+        val key = storageKey(messageId, fileIndex, clientMessageId)
 
-        mutex.withLock {
-            if (PlatformFileSystem.exists(path)) return "file://$path"
+        getCached(messageId, fileIndex, clientMessageId)?.let { uri ->
+            AttachmentMediaLog.diskCache(
+                "getOrDecrypt_hit",
+                "key" to key,
+                "msgId" to messageId,
+                "clientId" to clientMessageId,
+                "uri" to uri,
+            )
+            return uri
         }
 
-        val bytes = runCatching {
-            withContext(Dispatchers.Default) {
-                decryptFile(file, envelope, currentUserId)
-            }
-        }.getOrNull() ?: return null
+        AttachmentMediaLog.diskCache(
+            "getOrDecrypt_miss",
+            "key" to key,
+            "msgId" to messageId,
+            "clientId" to clientMessageId,
+            "file" to file.path,
+        )
 
-        mutex.withLock {
-            PlatformFileSystem.writeBytes(path, bytes)
+        cacheMutex.withLock { resolveUriLocked(key) }?.let { return it }
+
+        val label = AttachmentMediaLog.messageLabel(messageLabel)
+        val uri = withContext(Dispatchers.Default + NonCancellable) {
+            runCatching {
+                AttachmentDownloadScheduler.run(storageKey = key, messageId = messageId) {
+                    AttachmentMediaLog.download(
+                        "decrypt_start",
+                        "key" to key,
+                        "file" to file.path,
+                        "msgId" to messageId,
+                        "visible" to AttachmentDownloadVisibility.isPrioritized(messageId),
+                        "msg" to label,
+                    )
+                    decryptAndPersist(
+                        key = key,
+                        messageId = messageId,
+                        fileIndex = fileIndex,
+                        clientMessageId = clientMessageId,
+                        file = file,
+                        envelope = envelope,
+                        currentUserId = currentUserId,
+                        messageLabel = label,
+                    )
+                }
+            }.onFailure { error ->
+                ApiClient.clearPartialEncryptedDownload(key)
+                AttachmentMediaLog.download(
+                    "decrypt_exception",
+                    "key" to key,
+                    "msgId" to messageId,
+                    "msg" to label,
+                    "err" to (error.message ?: error::class.simpleName),
+                )
+                AttachmentDownloadNotifier.emit(
+                    AttachmentDownloadProgress.Failed(
+                        storageKey = key,
+                        error = error.message ?: "decrypt_failed",
+                    ),
+                    messageLabel = label,
+                    messageId = messageId,
+                    fileIndex = fileIndex,
+                    clientMessageId = clientMessageId,
+                )
+            }.getOrNull()
         }
-        return "file://$path"
+        if (uri != null && messageId > 0) {
+            ensureDiskAliasForMessageId(messageId, fileIndex, clientMessageId)
+        }
+        return uri
     }
 
     suspend fun invalidateForMessage(messageId: Int) {
         val dir = ensureCacheDir() ?: return
         withContext(Dispatchers.Default) {
-            PlatformFileSystem.deleteFilesWithPrefix(dir, "img_${messageId}_")
+            cacheMutex.withLock {
+                memoryCache.keys.removeAll { it.startsWith("img_${messageId}_") }
+            }
+            runCatching {
+                PlatformFileSystem.deleteFilesWithPrefix(dir, "img_${messageId}_")
+            }
+            LocalDecodedImageCache.evictPrefix("img_${messageId}_")
         }
     }
 
-    suspend fun invalidateForFile(messageId: Int, fileIndex: Int, filePath: String) {
+    suspend fun invalidateForClientMessage(clientMessageId: String) {
+        val cid = clientMessageId.trim()
+        if (cid.isEmpty()) return
+        val prefix = "img_c_${sanitizeKeyPart(cid)}_"
         val dir = ensureCacheDir() ?: return
-        val path = "$dir/${key(messageId, fileIndex, filePath)}"
         withContext(Dispatchers.Default) {
-            PlatformFileSystem.delete(path)
+            cacheMutex.withLock {
+                memoryCache.keys.removeAll { it.startsWith(prefix) }
+            }
+            runCatching {
+                PlatformFileSystem.deleteFilesWithPrefix(dir, prefix)
+            }
+            LocalDecodedImageCache.evictPrefix(prefix)
         }
     }
+
+    suspend fun invalidateForFile(
+        messageId: Int,
+        fileIndex: Int,
+        clientMessageId: String? = null,
+    ) {
+        val key = storageKey(messageId, fileIndex, clientMessageId)
+        withContext(Dispatchers.Default) {
+            cacheMutex.withLock { memoryCache.remove(key) }
+            diskPath(key)?.let { invalidatePath(it) }
+            LocalDecodedImageCache.evict(key)
+        }
+    }
+
+    suspend fun seedFromLocalFile(
+        messageId: Int,
+        fileIndex: Int,
+        localFileUri: String,
+        clientMessageId: String? = null,
+    ): String? = withContext(Dispatchers.Default + NonCancellable) {
+        val key = storageKey(messageId, fileIndex, clientMessageId)
+        cacheMutex.withLock { resolveUriLocked(key) }?.let { existing ->
+            AttachmentMediaLog.diskCache(
+                "seed_skip_exists",
+                "key" to key,
+                "uri" to existing,
+            )
+            return@withContext existing
+        }
+        val t0 = AttachmentMediaLog.nowMs()
+        val bytes = runCatching {
+            ru.fromchat.core.cache.readOutboundFileBytes(localFileUri)
+        }.getOrNull()
+        if (bytes == null) {
+            AttachmentMediaLog.diskCache("seed_read_failed", "key" to key, "src" to localFileUri)
+            return@withContext null
+        }
+        val uri = cacheMutex.withLock {
+            resolveUriLocked(key) ?: writeCacheLocked(key, bytes)
+        }
+        AttachmentMediaLog.diskCache(
+            if (uri != null) "seed_ok" else "seed_write_failed",
+            "key" to key,
+            "bytes" to bytes.size,
+            "ms" to (AttachmentMediaLog.nowMs() - t0),
+            "uri" to uri,
+        )
+        uri
+    }
+
+    private suspend fun decryptAndPersist(
+        key: String,
+        messageId: Int,
+        fileIndex: Int,
+        clientMessageId: String?,
+        file: DmFile,
+        envelope: DmEnvelope,
+        currentUserId: Int?,
+        messageLabel: String? = null,
+    ): String? {
+        cacheMutex.withLock { resolveUriLocked(key) }?.let { return it }
+        AttachmentDownloadNotifier.emit(
+            AttachmentDownloadProgress.InProgress(key, 1),
+            messageLabel = messageLabel,
+            messageId = messageId,
+            fileIndex = fileIndex,
+            clientMessageId = clientMessageId,
+        )
+        val t0 = AttachmentMediaLog.nowMs()
+        val bytes = runCatching {
+            decryptFile(
+                file = file,
+                envelope = envelope,
+                currentUserId = currentUserId,
+                downloadResumeKey = key,
+                onDownloadProgress = { percent ->
+                    AttachmentDownloadNotifier.emit(
+                        AttachmentDownloadProgress.InProgress(key, percent.coerceIn(0, 100)),
+                        messageLabel = messageLabel,
+                        messageId = messageId,
+                        fileIndex = fileIndex,
+                        clientMessageId = clientMessageId,
+                    )
+                },
+            )
+        }.onFailure { error ->
+            ApiClient.clearPartialEncryptedDownload(key)
+            AttachmentMediaLog.download(
+                "decrypt_failed",
+                "key" to key,
+                "msgId" to messageId,
+                "msg" to messageLabel,
+                "file" to file.path,
+                "err" to (error.message ?: error::class.simpleName),
+            )
+            AttachmentDownloadNotifier.emit(
+                AttachmentDownloadProgress.Failed(key, error.message ?: "download_failed"),
+                messageLabel = messageLabel,
+                messageId = messageId,
+                fileIndex = fileIndex,
+                clientMessageId = clientMessageId,
+            )
+        }.getOrNull()
+        if (bytes == null) {
+            ApiClient.clearPartialEncryptedDownload(key)
+            return null
+        }
+        AttachmentDownloadNotifier.emit(
+            AttachmentDownloadProgress.InProgress(key, 99),
+            messageLabel = messageLabel,
+            messageId = messageId,
+            fileIndex = fileIndex,
+            clientMessageId = clientMessageId,
+        )
+        val uri = cacheMutex.withLock {
+            resolveUriLocked(key) ?: writeCacheLocked(key, bytes)
+        }
+        if (uri == null) {
+            ApiClient.clearPartialEncryptedDownload(key)
+            AttachmentMediaLog.download(
+                "decrypt_persist_failed",
+                "key" to key,
+                "msg" to messageLabel,
+                "bytes" to bytes.size,
+            )
+            AttachmentDownloadNotifier.emit(
+                AttachmentDownloadProgress.Failed(key, "cache_write_failed"),
+                messageLabel = messageLabel,
+                messageId = messageId,
+                fileIndex = fileIndex,
+                clientMessageId = clientMessageId,
+            )
+            return null
+        }
+        AttachmentMediaLog.download(
+            "decrypt_persist_ok",
+            "key" to key,
+            "bytes" to bytes.size,
+            "ms" to (AttachmentMediaLog.nowMs() - t0),
+            "uri" to uri,
+            "msg" to messageLabel,
+        )
+        AttachmentDownloadNotifier.emit(
+            AttachmentDownloadProgress.Success(storageKey = key, messageId = messageId),
+            messageLabel = messageLabel,
+            messageId = messageId,
+            fileIndex = fileIndex,
+            clientMessageId = clientMessageId,
+        )
+        return uri
+    }
+
+    private fun resolveUriLocked(storageKey: String): String? {
+        memoryCache[storageKey]?.let { uri ->
+            if (uriFileExists(uri)) return uri
+            memoryCache.remove(storageKey)
+        }
+        val fromDisk = readDisk(storageKey) ?: return null
+        memoryCache[storageKey] = fromDisk
+        AttachmentMediaLog.diskCache("disk_hit", "key" to storageKey, "uri" to fromDisk)
+        return fromDisk
+    }
+
+    private fun uriFileExists(fileUri: String): Boolean {
+        val path = fileUri.removePrefix("file://")
+        return path.isNotEmpty() && PlatformFileSystem.exists(path)
+    }
+
+    private fun ensureCacheDir(): String? {
+        val base = PlatformFileSystem.getAppCacheDirectory()
+        if (base.isEmpty()) return null
+        val path = cacheDir?.takeIf { it.endsWith(SUBDIR) } ?: "$base/$SUBDIR"
+        return runCatching {
+            PlatformFileSystem.ensureDirectory(path)
+            if (!PlatformFileSystem.exists(path)) return null
+            cacheDir = path
+            path
+        }.getOrNull()
+    }
+
+    private fun sanitizeKeyPart(value: String): String =
+        value.replace(Regex("[^a-zA-Z0-9._-]"), "_")
+
+    private fun diskPath(storageKey: String): String? {
+        val dir = ensureCacheDir() ?: return null
+        return "$dir/$storageKey"
+    }
+
+    private fun readDisk(storageKey: String): String? {
+        val path = diskPath(storageKey) ?: return null
+        if (!PlatformFileSystem.exists(path)) return null
+        return "file://$path"
+    }
+
+    private fun writeCacheLocked(storageKey: String, bytes: ByteArray): String? {
+        if (bytes.isEmpty()) return null
+        val path = diskPath(storageKey) ?: return null
+        return runCatching {
+            PlatformFileSystem.writeBytes(path, bytes)
+            if (!PlatformFileSystem.exists(path)) return null
+            val uri = "file://$path"
+            memoryCache[storageKey] = uri
+            uri
+        }.getOrElse {
+            invalidatePath(path)
+            null
+        }
+    }
+
+    private fun invalidatePath(path: String) {
+        runCatching { PlatformFileSystem.delete(path) }
+    }
 }

app/shared/src/commonMain/kotlin/ru/fromchat/ui/chat/ImageFullscreenPreview.kt

@@ -61,16 +61,17 @@ import androidx.compose.ui.input.pointer.pointerInput
 import androidx.compose.ui.layout.ContentScale
 import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.unit.dp
-import coil3.compose.AsyncImage
+import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
+import kotlinx.coroutines.withContext
 import kotlinx.coroutines.coroutineScope
 import kotlinx.coroutines.delay
+import kotlinx.coroutines.joinAll
 import kotlinx.coroutines.launch
-import kotlinx.datetime.TimeZone
 import org.jetbrains.compose.resources.stringResource
 import ru.fromchat.Res
-import kotlinx.datetime.toLocalDateTime
 import ru.fromchat.api.Message
+import ru.fromchat.api.formatMessageDateTimeLocal
 import ru.fromchat.*
 import ru.fromchat.ui.BackHandler
 import ru.fromchat.ui.LocalSystemBarsVisibility
@@ -78,9 +79,6 @@ import kotlin.math.abs
 import kotlin.math.max
 import kotlin.math.min
 import kotlin.math.roundToInt
-import kotlin.time.ExperimentalTime
-import kotlin.time.Instant
-
 private val MENU_BG_ALPHA = 0.5f
 
 private data class InitialTransform(
@@ -91,22 +89,6 @@ private data class InitialTransform(
     val bgAlpha: Float
 )
 
-@OptIn(ExperimentalTime::class)
-private fun formatDateTime(timestamp: String): String {
-    return try {
-        Instant.parse(timestamp).toLocalDateTime(TimeZone.currentSystemDefault()).let {
-            val hour = it.hour.toString().padStart(2, '0')
-            val minute = it.minute.toString().padStart(2, '0')
-            val month = (it.month.ordinal + 1).toString().padStart(2, '0')
-            val day = it.day.toString().padStart(2, '0')
-            val year = it.year
-            "$month/$day/$year $hour:$minute"
-        }
-    } catch (_: Exception) {
-        timestamp
-    }
-}
-
 @Composable
 fun ImageFullscreenPreview(
     message: Message,
@@ -133,18 +115,33 @@ fun ImageFullscreenPreview(
     val envelope = message.dmEnvelope
     val thumbnailBase64 = message.fileThumbnails?.getOrNull(fileIndex)
 
-    var cachedPath by remember(message.id, fileIndex, file.path) {
-        mutableStateOf(DecryptedImageCache.getCached(message.id, fileIndex, file.path))
+    val cacheClientId = message.client_message_id?.trim()?.takeIf { it.isNotEmpty() }
+    val decryptCacheKey = remember(message.id, fileIndex, cacheClientId) {
+        DecryptedImageCache.storageKey(message.id, fileIndex, cacheClientId)
     }
-    val thumbnailBytes = remember(thumbnailBase64) {
-        thumbnailBase64?.let { runCatching { com.pr0gramm3r101.utils.crypto.Base64.decode(it) }.getOrNull() }
+    val fsCacheKey = remember(decryptCacheKey) {
+        LocalDecodedImageCache.fullscreenCacheKey(decryptCacheKey)
     }
-
-    LaunchedEffect(message.id, fileIndex, file.path, envelope) {
-        cachedPath = DecryptedImageCache.getOrDecrypt(message.id, fileIndex, file, envelope, currentUserId)
+    var cachedPath by remember(decryptCacheKey) {
+        mutableStateOf(DecryptedImageCache.getCached(message.id, fileIndex, cacheClientId))
     }
-
-    val imageModel = cachedPath ?: thumbnailBytes
+    var previewBitmap by remember(decryptCacheKey) {
+        mutableStateOf(LocalDecodedImageCache.peekFull(decryptCacheKey))
+    }
+    var fullscreenBitmap by remember(fsCacheKey) {
+        mutableStateOf(LocalDecodedImageCache.peekFullscreen(decryptCacheKey))
+    }
+    val hasInstantBitmap = previewBitmap != null || fullscreenBitmap != null
+    val openAspectFromBitmap = previewBitmap?.let { it.width.toFloat() / it.height.toFloat() }
+    val layoutAspectHint = imageAspectRatioForMessage(
+        fileAspectRatios = message.fileAspectRatios,
+        fileDimensions = message.fileDimensions,
+        pendingFileAspectRatio = message.pendingFileAspectRatio,
+        fileIndex = fileIndex,
+        confirmed = message.id > 0,
+    )
+    val thumbLayoutAspect = thumbnailBounds?.takeIf { it.width > 0f && it.height > 0f }
+        ?.let { bounds -> bounds.width / bounds.height }
 
     var menusVisible by remember { mutableStateOf(true) }
     var dismissRequested by remember { mutableStateOf(false) }
@@ -186,11 +183,45 @@ fun ImageFullscreenPreview(
         ) {
             val containerWidth = constraints.maxWidth.toFloat()
             val containerHeight = constraints.maxHeight.toFloat()
-            val fileAspectRatio = message.fileAspectRatios?.getOrNull(fileIndex)?.takeIf { it > 0f }
-            val contentHeightAtScale1 = if (fileAspectRatio != null) containerWidth / fileAspectRatio else containerHeight
+            val fullscreenDecodeSize = remember(constraints.maxWidth, constraints.maxHeight) {
+                ChatPreviewDecodeSize(
+                    widthPx = constraints.maxWidth.coerceAtLeast(1),
+                    heightPx = constraints.maxHeight.coerceAtLeast(1),
+                )
+            }
 
-            when (val model = imageModel) {
-                null -> {
+            LaunchedEffect(decryptCacheKey, fsCacheKey, fullscreenDecodeSize) {
+                val uri = cachedPath ?: DecryptedImageCache.getCached(message.id, fileIndex, cacheClientId)
+                    ?: DecryptedImageCache.getOrDecrypt(
+                        messageId = message.id,
+                        fileIndex = fileIndex,
+                        file = file,
+                        envelope = envelope,
+                        currentUserId = currentUserId,
+                        clientMessageId = cacheClientId,
+                        messageLabel = message.content,
+                    ).also { cachedPath = it }
+                if (uri == null) return@LaunchedEffect
+                val hiRes = withContext(Dispatchers.Default) {
+                    LocalDecodedImageCache.loadFullscreen(decryptCacheKey, uri, fullscreenDecodeSize)
+                }
+                if (hiRes != null) {
+                    fullscreenBitmap = hiRes
+                }
+            }
+
+            val displayBitmap = fullscreenBitmap ?: previewBitmap
+            val displayAspect = displayBitmap?.let { bmp ->
+                bmp.width.toFloat() / bmp.height.toFloat()
+            } ?: message.fileAspectRatios?.getOrNull(fileIndex)?.takeIf { it > 0f }
+            val contentHeightAtScale1 = if (displayAspect != null) {
+                containerWidth / displayAspect
+            } else {
+                containerHeight
+            }
+
+            when {
+                displayBitmap == null -> {
                     Box(
                         modifier = Modifier
                             .fillMaxSize()
@@ -205,14 +236,23 @@ fun ImageFullscreenPreview(
                     )
                 }
                 else -> {
+                    val layoutAspect = openAspectFromBitmap
+                        ?: thumbLayoutAspect
+                        ?: layoutAspectHint
+                        ?: displayAspect
+                    val layoutContentHeight = if (layoutAspect != null) {
+                        containerWidth / layoutAspect
+                    } else {
+                        contentHeightAtScale1
+                    }
                     val initial = remember(
-                        thumbnailBounds, containerWidth, containerHeight, contentHeightAtScale1
+                        thumbnailBounds, containerWidth, containerHeight, layoutContentHeight,
                     ) {
-                        if (thumbnailBounds != null && fileAspectRatio != null) {
-                            val fullTop = (containerHeight - contentHeightAtScale1) / 2f
+                        if (thumbnailBounds != null && layoutAspect != null) {
+                            val fullTop = (containerHeight - layoutContentHeight) / 2f
                             val fullCenter = Offset(
                                 x = containerWidth / 2f,
-                                y = fullTop + contentHeightAtScale1 / 2f
+                                y = fullTop + layoutContentHeight / 2f,
                             )
                             val thumbCenter = thumbnailBounds.center
                             val thumbWidth = thumbnailBounds.width
@@ -244,10 +284,10 @@ fun ImageFullscreenPreview(
                             hasPlayedOpenAnimation = true
                             isOpenAnimationPlaying = true
 
-                            val fullTop = (containerHeight - contentHeightAtScale1) / 2f
+                            val fullTop = (containerHeight - layoutContentHeight) / 2f
                             val fullCenter = Offset(
                                 x = containerWidth / 2f,
-                                y = fullTop + contentHeightAtScale1 / 2f
+                                y = fullTop + layoutContentHeight / 2f,
                             )
                             val thumbCenter = thumbnailBounds.center
                             val thumbWidth = thumbnailBounds.width
@@ -261,17 +301,24 @@ fun ImageFullscreenPreview(
                             offsetXAnim.snapTo(startOffset.x)
                             offsetYAnim.snapTo(startOffset.y)
                             cornerRadiusAnim.snapTo(12f)
-                            backgroundAlpha.snapTo(0f)
+                            backgroundAlpha.snapTo(if (hasInstantBitmap) 1f else 0f)
                             menusVisible = false
 
                             coroutineScope {
-                                launch { scaleAnim.animateTo(1f, tween(250)) }
-                                launch { offsetXAnim.animateTo(0f, tween(250)) }
-                                launch { offsetYAnim.animateTo(0f, tween(250)) }
-                                launch { cornerRadiusAnim.animateTo(0f, tween(250)) }
-                                launch { backgroundAlpha.animateTo(1f, tween(250)) }
+                                joinAll(
+                                    launch { scaleAnim.animateTo(1f, tween(280)) },
+                                    launch { offsetXAnim.animateTo(0f, tween(280)) },
+                                    launch { offsetYAnim.animateTo(0f, tween(280)) },
+                                    launch { cornerRadiusAnim.animateTo(0f, tween(280)) },
+                                    launch {
+                                        if (!hasInstantBitmap) {
+                                            backgroundAlpha.animateTo(1f, tween(280))
+                                        }
+                                    },
+                                )
                             }
-
+                            scale = 1f
+                            offset = Offset.Zero
                             isOpenAnimationPlaying = false
                             menusVisible = true
                         }
@@ -296,10 +343,10 @@ fun ImageFullscreenPreview(
                             val wasOpenAnimating = isOpenAnimationPlaying
                             isOpenAnimationPlaying = false
 
-                            val fullTop = (containerHeight - contentHeightAtScale1) / 2f
+                            val fullTop = (containerHeight - layoutContentHeight) / 2f
                             val fullCenter = Offset(
                                 x = containerWidth / 2f,
-                                y = fullTop + contentHeightAtScale1 / 2f
+                                y = fullTop + layoutContentHeight / 2f,
                             )
                             val thumbCenter = thumbnailBounds.center
                             val thumbWidth = thumbnailBounds.width
@@ -385,7 +432,7 @@ fun ImageFullscreenPreview(
 
                             val clampedScale = scale.coerceIn(1f, 10f)
                             val scaledW = containerWidth * clampedScale
-                            val scaledH = contentHeightAtScale1 * clampedScale
+                            val scaledH = layoutContentHeight * clampedScale
                             val maxOffsetX = max(0f, (scaledW - containerWidth) / 2f)
                             val maxOffsetY = max(0f, (scaledH - containerHeight) / 2f)
                             val clampedOffset = when {
@@ -420,7 +467,10 @@ fun ImageFullscreenPreview(
                         val raw = (abs(dragY) / (containerHeight * 0.75f)).coerceIn(0f, 1f)
                         raw * raw
                     } else 0f
-                    val effectiveBackgroundAlpha = (if (isInitialOpenState) 0f else backgroundAlpha.value) * (1f - positionBasedProgress)
+                    val effectiveBackgroundAlpha = (
+                        if (isInitialOpenState && !hasInstantBitmap) 0f
+                        else backgroundAlpha.value
+                    ) * (1f - positionBasedProgress)
                     SideEffect { effectiveBgAlpha = effectiveBackgroundAlpha }
 
                     val sharedElementModifier = if (sharedImageKey != null && sharedTransitionScope != null && animatedVisibilityScope != null) {
@@ -431,15 +481,18 @@ fun ImageFullscreenPreview(
                             )
                         }
                     } else Modifier
-                    val sizeModifier = if (fileAspectRatio != null) Modifier.fillMaxWidth().aspectRatio(fileAspectRatio)
-                    else Modifier.fillMaxSize()
+                    val sizeModifier = if (layoutAspect != null) {
+                        Modifier.fillMaxWidth().aspectRatio(layoutAspect)
+                    } else {
+                        Modifier.fillMaxSize()
+                    }
                     Box(
                         modifier = Modifier
                             .fillMaxSize()
                             .then(
                                 if (isTransitioning) Modifier
                                 else Modifier.pointerInput(
-                                    containerWidth, containerHeight, contentHeightAtScale1,
+                                    containerWidth, containerHeight, layoutContentHeight,
                                     bottomInsetPx, scope
                                 ) {
                                     detectTransformGestures(
@@ -474,7 +527,7 @@ fun ImageFullscreenPreview(
                                                 centroid.y - centerY - pivotOffsetY * zoomChange
                                             )
 
-                                            val contentHeightAtNewScale = contentHeightAtScale1 * newScale
+                                            val contentHeightAtNewScale = layoutContentHeight * newScale
                                             val scaledW = containerWidth * newScale
                                             val maxOffsetX = max(0f, (scaledW - containerWidth) / 2f)
                                             val maxOffsetYRaw = max(0f, (contentHeightAtNewScale - containerHeight) / 2f)
@@ -496,7 +549,7 @@ fun ImageFullscreenPreview(
                                             }
                                             offset = Offset(newX, newY)
                                         } else {
-                                            val contentHeightAtCurrentScale = contentHeightAtScale1 * scale
+                                            val contentHeightAtCurrentScale = layoutContentHeight * scale
                                             val canScrollVertically = contentHeightAtCurrentScale > containerHeight
                                             val absDx = abs(panChange.x)
                                             val absDy = abs(panChange.y)
@@ -564,8 +617,8 @@ fun ImageFullscreenPreview(
                                 .then(sharedElementModifier)
                                 .offset { IntOffset(offsetXAnim.value.roundToInt(), offsetYAnim.value.roundToInt()) }
                         ) {
-                            AsyncImage(
-                                model = model,
+                            FullscreenBitmapImage(
+                                bitmap = displayBitmap,
                                 contentDescription = file.name,
                                 modifier = Modifier
                                     .fillMaxSize()
@@ -578,7 +631,7 @@ fun ImageFullscreenPreview(
                                         shape = androidx.compose.foundation.shape.RoundedCornerShape((cornerRadiusAnim.value / scale).dp)
                                         clip = true
                                     },
-                                contentScale = ContentScale.FillWidth
+                                contentScale = ContentScale.Fit
                             )
                         }
                     }
@@ -587,18 +640,23 @@ fun ImageFullscreenPreview(
         }
 
         // Top bar: back, display name + date/time, 3-dot menu
-        AnimatedVisibility(
-            visible = effectiveMenusVisible,
-            enter = androidx.compose.animation.fadeIn(),
-            exit = androidx.compose.animation.fadeOut(),
-            modifier = Modifier.align(Alignment.TopStart).fillMaxWidth()
+        Box(
+            modifier = Modifier
+                .align(Alignment.TopStart)
+                .fillMaxWidth()
+                .windowInsetsPadding(WindowInsets.systemBars),
         ) {
-            Row(
-                modifier = Modifier
-                    .fillMaxWidth()
-                    .background(Color.Black.copy(alpha = MENU_BG_ALPHA))
-                    .windowInsetsPadding(WindowInsets.systemBars)
-                    .padding(horizontal = 8.dp, vertical = 12.dp),
+            AnimatedVisibility(
+                visible = effectiveMenusVisible,
+                enter = androidx.compose.animation.fadeIn(),
+                exit = androidx.compose.animation.fadeOut(),
+                modifier = Modifier.fillMaxWidth(),
+            ) {
+                Row(
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .background(Color.Black.copy(alpha = MENU_BG_ALPHA))
+                        .padding(horizontal = 8.dp, vertical = 12.dp),
                 verticalAlignment = Alignment.CenterVertically,
                 horizontalArrangement = Arrangement.SpaceBetween
             ) {
@@ -619,7 +677,7 @@ fun ImageFullscreenPreview(
                         color = Color.White
                     )
                     Text(
-                        text = formatDateTime(message.timestamp),
+                        text = formatMessageDateTimeLocal(message.timestamp),
                         style = MaterialTheme.typography.bodySmall,
                         color = Color.White.copy(alpha = 0.8f)
                     )
@@ -682,29 +740,36 @@ fun ImageFullscreenPreview(
                     }
                 }
             }
+            }
         }
 
         // Bottom: message text
-        AnimatedVisibility(
-            visible = effectiveMenusVisible && message.content.isNotBlank(),
-            enter = androidx.compose.animation.fadeIn(),
-            exit = androidx.compose.animation.fadeOut(),
-            modifier = Modifier.align(Alignment.BottomStart).fillMaxWidth()
+        Box(
+            modifier = Modifier
+                .align(Alignment.BottomStart)
+                .fillMaxWidth()
+                .windowInsetsPadding(WindowInsets.systemBars),
         ) {
-            if (message.content.isNotBlank()) {
-                Box(
-                    modifier = Modifier
-                        .fillMaxWidth()
-                        .background(Color.Black.copy(alpha = MENU_BG_ALPHA))
-                        .windowInsetsPadding(WindowInsets.systemBars)
-                        .padding(16.dp)
-                ) {
+            AnimatedVisibility(
+                visible = effectiveMenusVisible && message.content.isNotBlank(),
+                enter = androidx.compose.animation.fadeIn(),
+                exit = androidx.compose.animation.fadeOut(),
+                modifier = Modifier.fillMaxWidth(),
+            ) {
+                if (message.content.isNotBlank()) {
+                    Box(
+                        modifier = Modifier
+                            .fillMaxWidth()
+                            .background(Color.Black.copy(alpha = MENU_BG_ALPHA))
+                            .padding(16.dp),
+                    ) {
                     Text(
                         text = message.content,
                         style = MaterialTheme.typography.bodyMedium,
                         color = Color.White
                     )
                 }
+                }
             }
         }
     }

app/shared/src/commonMain/kotlin/ru/fromchat/ui/chat/LocalDecodedImageCache.kt

@@ -0,0 +1,172 @@
+package ru.fromchat.ui.chat
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import androidx.compose.ui.graphics.ImageBitmap
+import androidx.compose.ui.platform.LocalDensity
+import androidx.compose.ui.unit.Density
+import androidx.compose.ui.unit.Dp
+import kotlin.math.ceil
+
+/** Target decode dimensions in physical pixels for a chat attachment tile. */
+data class ChatPreviewDecodeSize(val widthPx: Int, val heightPx: Int) {
+    init {
+        require(widthPx > 0 && heightPx > 0)
+    }
+
+    val longEdgePx: Int get() = maxOf(widthPx, heightPx)
+}
+
+object LocalDecodedImageCache {
+    private const val THUMB_SUFFIX = "#thumb"
+    private const val FULLSCREEN_SUFFIX = "#fs"
+
+    fun previewCacheKey(storageKey: String): String = storageKey
+
+    fun fullscreenCacheKey(storageKey: String): String = storageKey + FULLSCREEN_SUFFIX
+
+    fun peekFull(storageKey: String): ImageBitmap? = PlatformDecodedBitmapCache.get(storageKey)
+
+    fun peekFullscreen(storageKey: String): ImageBitmap? =
+        PlatformDecodedBitmapCache.get(fullscreenCacheKey(storageKey))
+
+    fun peekThumb(storageKey: String): ImageBitmap? =
+        PlatformDecodedBitmapCache.get(storageKey + THUMB_SUFFIX)
+
+    fun isBelowTarget(bitmap: ImageBitmap, target: ChatPreviewDecodeSize): Boolean =
+        bitmap.width < target.widthPx || bitmap.height < target.heightPx
+
+    /** Avoid re-decoding on minor target growth after layout measure. */
+    fun needsUpscale(bitmap: ImageBitmap, target: ChatPreviewDecodeSize): Boolean {
+        if (bitmap.width < target.widthPx * 0.88f) return true
+        if (bitmap.height < target.heightPx * 0.88f) return true
+        return false
+    }
+
+    suspend fun loadFull(
+        storageKey: String,
+        fileUri: String,
+        target: ChatPreviewDecodeSize,
+    ): ImageBitmap? = loadIntoCache(previewCacheKey(storageKey), fileUri, target)
+
+    suspend fun loadFullscreen(
+        storageKey: String,
+        fileUri: String,
+        target: ChatPreviewDecodeSize,
+    ): ImageBitmap? = loadIntoCache(fullscreenCacheKey(storageKey), fileUri, target)
+
+    private suspend fun loadIntoCache(
+        cacheKey: String,
+        fileUri: String,
+        target: ChatPreviewDecodeSize,
+    ): ImageBitmap? {
+        PlatformDecodedBitmapCache.get(cacheKey)?.let { cached ->
+            if (!needsUpscale(cached, target)) {
+                AttachmentMediaLog.bitmapCache(
+                    "memory_hit",
+                    "cacheKey" to cacheKey,
+                    "bmp" to "${cached.width}x${cached.height}",
+                    "target" to "${target.widthPx}x${target.heightPx}",
+                )
+                return cached
+            }
+            AttachmentMediaLog.bitmapCache(
+                "memory_evict_upscale",
+                "cacheKey" to cacheKey,
+                "bmp" to "${cached.width}x${cached.height}",
+                "target" to "${target.widthPx}x${target.heightPx}",
+            )
+            PlatformDecodedBitmapCache.remove(cacheKey)
+        }
+        val path = fileUri.removePrefix("file://")
+        if (path.isEmpty()) return null
+        val t0 = AttachmentMediaLog.nowMs()
+        val bitmap = decodeLocalImageFile(path, target.widthPx, target.heightPx)
+        val elapsedMs = AttachmentMediaLog.nowMs() - t0
+        if (bitmap == null) {
+            AttachmentMediaLog.bitmapCache(
+                "decode_failed",
+                "cacheKey" to cacheKey,
+                "path" to path,
+                "target" to "${target.widthPx}x${target.heightPx}",
+                "ms" to elapsedMs,
+            )
+            return null
+        }
+        PlatformDecodedBitmapCache.put(cacheKey, bitmap)
+        AttachmentMediaLog.bitmapCache(
+            "decode_ok",
+            "cacheKey" to cacheKey,
+            "bmp" to "${bitmap.width}x${bitmap.height}",
+            "target" to "${target.widthPx}x${target.heightPx}",
+            "ms" to elapsedMs,
+        )
+        return bitmap
+    }
+
+    suspend fun loadThumb(
+        storageKey: String,
+        bytes: ByteArray,
+        displayTarget: ChatPreviewDecodeSize,
+    ): ImageBitmap? {
+        val key = storageKey + THUMB_SUFFIX
+        PlatformDecodedBitmapCache.get(key)?.let { return it }
+        val bitmap = decodeImageBytes(
+            bytes = bytes,
+            reqWidthPx = displayTarget.widthPx,
+            reqHeightPx = displayTarget.heightPx,
+        ) ?: return null
+        PlatformDecodedBitmapCache.put(key, bitmap)
+        return bitmap
+    }
+
+    fun evict(storageKey: String) {
+        PlatformDecodedBitmapCache.remove(previewCacheKey(storageKey))
+        PlatformDecodedBitmapCache.remove(fullscreenCacheKey(storageKey))
+        PlatformDecodedBitmapCache.remove(storageKey + THUMB_SUFFIX)
+    }
+
+    fun evictPrefix(prefix: String) = PlatformDecodedBitmapCache.evictPrefix(prefix)
+}
+
+fun computeChatPreviewDecodeSize(
+    previewTileMax: Dp,
+    aspectRatio: Float?,
+    density: Density,
+): ChatPreviewDecodeSize = with(density) {
+    val maxPx = ceil(previewTileMax.toPx()).toInt().coerceAtLeast(1)
+    val ratio = aspectRatio?.takeIf { it.isFinite() && it > 0f } ?: 1f
+    if (ratio >= 1f) {
+        ChatPreviewDecodeSize(
+            widthPx = maxPx,
+            heightPx = ceil(maxPx / ratio).toInt().coerceAtLeast(1),
+        )
+    } else {
+        ChatPreviewDecodeSize(
+            widthPx = ceil(maxPx * ratio).toInt().coerceAtLeast(1),
+            heightPx = maxPx,
+        )
+    }
+}
+
+@Composable
+internal fun rememberChatPreviewDecodeSize(
+    previewTileMax: Dp,
+    aspectRatio: Float?,
+): ChatPreviewDecodeSize {
+    val density = LocalDensity.current
+    return remember(density, previewTileMax, aspectRatio) {
+        computeChatPreviewDecodeSize(previewTileMax, aspectRatio, density)
+    }
+}
+
+expect object PlatformDecodedBitmapCache {
+    fun get(key: String): ImageBitmap?
+    fun put(key: String, bitmap: ImageBitmap)
+    fun remove(key: String)
+    fun evictPrefix(prefix: String)
+}
+
+expect fun decodeLocalImageFile(absolutePath: String, reqWidthPx: Int, reqHeightPx: Int): ImageBitmap?
+
+expect fun decodeImageBytes(bytes: ByteArray, reqWidthPx: Int, reqHeightPx: Int): ImageBitmap?

app/shared/src/commonMain/kotlin/ru/fromchat/ui/chat/MessageContextMenu.kt

@@ -19,6 +19,8 @@ import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.automirrored.rounded.Reply
+import androidx.compose.material.icons.rounded.Close
+import androidx.compose.material.icons.rounded.ContentCopy
 import androidx.compose.material.icons.rounded.Delete
 import androidx.compose.material.icons.rounded.Edit
 import androidx.compose.material3.Icon
@@ -49,6 +51,7 @@ import androidx.compose.ui.window.PopupProperties
 import org.jetbrains.compose.resources.stringResource
 import ru.fromchat.Res
 import ru.fromchat.api.Message
+import ru.fromchat.api.isQueuedOutbound
 import ru.fromchat.*
 import ru.fromchat.ui.scaleOnPress
 
@@ -58,6 +61,25 @@ data class ContextMenuState(
     val position: IntOffset = IntOffset(0, 0)
 )
 
+/** Which context-menu rows would be shown; used to auto-dismiss when actions change. */
+internal fun messageContextMenuFingerprint(
+    message: Message,
+    isAuthor: Boolean,
+    isReadOnly: Boolean,
+): String {
+    val isQueued = message.isQueuedOutbound() && isAuthor
+    val corrupted = message.isContentCorrupted
+    return buildString {
+        append("q=").append(isQueued)
+        append("|copy=").append(!corrupted)
+        if (!isQueued && !isReadOnly) {
+            append("|reply=1")
+            append("|edit=").append(isAuthor && !corrupted)
+            append("|del=").append(isAuthor)
+        }
+    }
+}
+
 @Suppress("AssignedValueIsNeverRead")
 @Composable
 fun MessageContextMenu(
@@ -67,6 +89,8 @@ fun MessageContextMenu(
     onReply: (Message) -> Unit,
     onEdit: (Message) -> Unit,
     onDelete: (Message) -> Unit,
+    onCopy: (Message) -> Unit,
+    onCancelSend: (Message) -> Unit,
     isReadOnly: Boolean = false,
     screenWidthPx: Int,
     screenHeightPx: Int,
@@ -126,6 +150,8 @@ fun MessageContextMenu(
                     onReply = {},
                     onEdit = {},
                     onDelete = {},
+                    onCopy = {},
+                    onCancelSend = {},
                     modifier = modifier.graphicsLayer(alpha = 0f),
                     animated = false,
                     withShadow = false,
@@ -212,6 +238,14 @@ fun MessageContextMenu(
                         onDelete(it)
                         onDismiss()
                     },
+                    onCopy = {
+                        onCopy(it)
+                        onDismiss()
+                    },
+                    onCancelSend = {
+                        onCancelSend(it)
+                        onDismiss()
+                    },
                     modifier = modifier,
                     animated = true,
                     scale = scale,
@@ -232,6 +266,8 @@ private fun ContextMenuContent(
     onReply: (Message) -> Unit,
     onEdit: (Message) -> Unit,
     onDelete: (Message) -> Unit,
+    onCopy: (Message) -> Unit,
+    onCancelSend: (Message) -> Unit,
     isReadOnly: Boolean = false,
     modifier: Modifier,
     animated: Boolean,
@@ -276,6 +312,9 @@ private fun ContextMenuContent(
     val labelReply = stringResource(Res.string.action_reply)
     val labelEdit = stringResource(Res.string.action_edit)
     val labelDelete = stringResource(Res.string.action_delete)
+    val labelCopy = stringResource(Res.string.action_copy)
+    val labelCancelSend = stringResource(Res.string.action_cancel_send)
+    val isQueued = message.isQueuedOutbound() && isAuthor
 
     Box(modifier = containerModifier) {
         Box(modifier = Modifier.matchParentSize().background(menuColor, menuShape))
@@ -285,27 +324,41 @@ private fun ContextMenuContent(
                 .verticalScroll(menuScrollState),
             verticalArrangement = Arrangement.spacedBy(itemSpacing)
         ) {
-            if (!isReadOnly) {
+            if (!message.isContentCorrupted) {
+                ContextMenuItem(
+                    icon = Icons.Rounded.ContentCopy,
+                    text = labelCopy,
+                    onClick = { onCopy(message) }
+                )
+            }
+            if (isQueued) {
+                ContextMenuItem(
+                    icon = Icons.Rounded.Close,
+                    text = labelCancelSend,
+                    onClick = { onCancelSend(message) },
+                    isError = true
+                )
+            } else if (!isReadOnly) {
                 ContextMenuItem(
                     icon = Icons.AutoMirrored.Rounded.Reply,
                     text = labelReply,
                     onClick = { onReply(message) }
                 )
-            }
-            if (isAuthor && !isReadOnly) {
-                ContextMenuItem(
-                    icon = Icons.Rounded.Edit,
-                    text = labelEdit,
-                    onClick = { onEdit(message) }
-                )
-            }
-            if (isAuthor && !isReadOnly) {
-                ContextMenuItem(
-                    icon = Icons.Rounded.Delete,
-                    text = labelDelete,
-                    onClick = { onDelete(message) },
-                    isError = true
-                )
+                if (isAuthor && !message.isContentCorrupted) {
+                    ContextMenuItem(
+                        icon = Icons.Rounded.Edit,
+                        text = labelEdit,
+                        onClick = { onEdit(message) }
+                    )
+                }
+                if (isAuthor) {
+                    ContextMenuItem(
+                        icon = Icons.Rounded.Delete,
+                        text = labelDelete,
+                        onClick = { onDelete(message) },
+                        isError = true
+                    )
+                }
             }
         }
     }
@@ -339,7 +392,11 @@ private fun ContextMenuItem(
             .scaleOnPress(
                 scale = 0.96f,
                 onClick = onClick,
-                indication = LocalIndication.current
+                indication = LocalIndication.current,
+                animationSpec = spring(
+                    dampingRatio = Spring.DampingRatioMediumBouncy,
+                    stiffness = Spring.StiffnessMedium,
+                ),
             )
             .padding(horizontal = 12.dp, vertical = 8.dp),
         contentAlignment = Alignment.CenterStart

app/shared/src/commonMain/kotlin/ru/fromchat/ui/chat/MessageItem.kt

@@ -51,14 +51,11 @@ import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import com.pr0gramm3r101.utils.conditional
-import kotlinx.datetime.TimeZone
-import kotlinx.datetime.toLocalDateTime
 import org.jetbrains.compose.resources.stringResource
 import ru.fromchat.Res
 import ru.fromchat.api.Message
+import ru.fromchat.api.formatMessageTimeLocal
 import ru.fromchat.*
-import kotlin.time.ExperimentalTime
-import kotlin.time.Instant
 
 private fun isMessageCorrupted(message: Message): Boolean {
     val files = message.files ?: return false
@@ -70,7 +67,6 @@ private fun isMessageCorrupted(message: Message): Boolean {
     }
 }
 
-@OptIn(ExperimentalTime::class)
 @Composable
 fun MessageItem(
     message: Message,
@@ -96,7 +92,7 @@ fun MessageItem(
         isMessageCorrupted(message)
     }
     val formattedTime = remember(message.timestamp) {
-        formatTime(message.timestamp)
+        formatMessageTimeLocal(message.timestamp)
     }
     val corruptedBody = stringResource(Res.string.message_corrupted)
     val editedSuffix = stringResource(Res.string.message_edited_suffix)
@@ -419,84 +415,86 @@ fun MessageItem(
                                 modifier = Modifier.padding(horizontal = 12.dp, vertical = 8.dp)
                             )
                         } else {
-                            val firstFile = message.files?.firstOrNull()
-                            val firstFileIsImage = firstFile?.let { isImageFilename(it.name) } ?: false
-                            val hasPendingServerImage = message.pendingFileUri != null &&
-                                firstFileIsImage &&
-                                message.dmEnvelope != null
-                            if (message.pendingFileUri != null) {
-                                val isPendingImage = message.pendingFilename?.let { isImageFilename(it) } ?: false
-                                val pendingImageFile = firstFile.takeIf { isPendingImage && hasPendingServerImage }
-                                val imageKey = if (isPendingImage) "img_${message.id}_0" else null
+                            val primaryFile = message.files?.firstOrNull()
+                            val primaryIsImage = primaryFile != null && isImageFilename(primaryFile.name)
+                            val showPrimaryImageSlot = pendingIsImage || primaryIsImage
+                            if (showPrimaryImageSlot) {
+                                val imageKey = imageAttachmentKey(message, 0)
+                                val awaitingServer = message.id < 0 && message.files.isNullOrEmpty()
+                                val isOutboundPendingImage = awaitingServer && pendingIsImage
+                                val awaitingServerAck = isOutboundPendingImage &&
+                                    message.uploadProgress == null
                                 AttachmentPreview(
-                                    file = pendingImageFile,
-                                    dmEnvelope = if (pendingImageFile != null) message.dmEnvelope else null,
-                                    currentUserId = if (pendingImageFile != null) currentUserId else null,
+                                    file = primaryFile,
+                                    dmEnvelope = message.dmEnvelope,
+                                    currentUserId = currentUserId,
                                     pendingFileUri = message.pendingFileUri,
                                     pendingFilename = message.pendingFilename,
-                                    isUploading = message.uploadProgress != null,
+                                    isUploading = isOutboundPendingImage,
+                                    awaitingServerAck = awaitingServerAck,
                                     uploadProgress = message.uploadProgress,
-                                    fileThumbnail = if (pendingImageFile != null) {
-                                        message.fileThumbnails?.firstOrNull()?.takeIf { it.isNotBlank() }
-                                    } else {
-                                        null
-                                    },
-                                    fileAspectRatio = if (pendingImageFile != null) {
-                                        message.fileAspectRatios?.firstOrNull()?.takeIf { it > 0f }
-                                            ?: message.pendingFileAspectRatio
-                                    } else {
-                                        message.pendingFileAspectRatio
-                                    },
-                                    fileSizeBytes = when {
-                                        pendingImageFile != null -> message.fileSizes?.firstOrNull()
-                                        !isPendingImage -> message.fileSizes?.firstOrNull()
-                                        else -> null
-                                    },
-                                    messageId = if (pendingImageFile != null && isPendingImage) message.id else null,
-                                    fileIndex = if (pendingImageFile != null && isPendingImage) 0 else null,
+                                    fileThumbnail = message.fileThumbnails?.firstOrNull()?.takeIf { it.isNotBlank() },
+                                    fileAspectRatio = imageAspectRatioForMessage(
+                                        fileAspectRatios = message.fileAspectRatios,
+                                        fileDimensions = message.fileDimensions,
+                                        pendingFileAspectRatio = message.pendingFileAspectRatio,
+                                        fileIndex = 0,
+                                        confirmed = message.id > 0,
+                                        hasLocalPreview = DecryptedImageCache.isDecryptedImageCacheUri(
+                                            message.pendingFileUri,
+                                        ),
+                                    ),
+                                    fileSizeBytes = message.fileSizes?.firstOrNull(),
+                                    messageId = message.id,
+                                    fileIndex = 0,
+                                    clientMessageId = message.client_message_id,
                                     onFileClick = null,
-                                    onImageClick = if (isPendingImage && imageKey != null) {
-                                        { onImageClick?.invoke(message, 0) }
-                                    } else {
-                                        null
-                                    },
-                                    onImageBounds = if (isPendingImage && imageKey != null && onImageBounds != null) {
+                                    onImageClick = { onImageClick?.invoke(message, 0) },
+                                    onImageBounds = if (onImageBounds != null) {
                                         { rect -> onImageBounds.invoke(imageKey, rect) }
                                     } else {
                                         null
                                     },
-                                    isExpanded = isPendingImage &&
-                                        imageKey != null &&
-                                        expandedImageKey != null &&
+                                    isExpanded = expandedImageKey != null &&
                                         expandedImageKey == imageKey &&
                                         !isImageClosing,
                                     isAuthor = isAuthor,
-                                    modifier = if (isPendingImage && firstContentIsImage) {
+                                    messageLabel = message.content,
+                                    modifier = if (firstContentIsImage) {
                                         Modifier.padding(all = 2.dp)
                                     } else {
-                                        Modifier.padding(
-                                            horizontal = if (isPendingImage) 2.dp else 12.dp,
-                                            vertical = if (isPendingImage) 2.dp else 4.dp
-                                        )
+                                        Modifier.padding(horizontal = 2.dp, vertical = 4.dp)
                                     }
                                 )
                             }
                             message.files?.forEachIndexed { index, file ->
-                                if (message.pendingFileUri != null && index == 0) return@forEachIndexed
+                                if (index == 0 && showPrimaryImageSlot && isImageFilename(file.name)) {
+                                    return@forEachIndexed
+                                }
                                 val isImage = isImageFilename(file.name)
-                                val imageKey = if (isImage) "img_${message.id}_$index" else null
+                                val imageKey = if (isImage) imageAttachmentKey(message, index) else null
                                 val isFirstImage = index == 0 && isImage
                                 AttachmentPreview(
                                     file = file,
                                     dmEnvelope = message.dmEnvelope,
                                     currentUserId = currentUserId,
-                                    pendingFileUri = null,
+                                    pendingFileUri = if (index == 0) message.pendingFileUri else null,
+                                    pendingFilename = if (index == 0) message.pendingFilename else null,
                                     isUploading = false,
                                     fileThumbnail = message.fileThumbnails?.getOrNull(index)?.takeIf { it.isNotBlank() },
-                                    fileAspectRatio = message.fileAspectRatios?.getOrNull(index)?.takeIf { it > 0f },
+                                    fileAspectRatio = imageAspectRatioForMessage(
+                                        fileAspectRatios = message.fileAspectRatios,
+                                        fileDimensions = message.fileDimensions,
+                                        pendingFileAspectRatio = message.pendingFileAspectRatio,
+                                        fileIndex = index,
+                                        confirmed = message.id > 0,
+                                        hasLocalPreview = index == 0 &&
+                                            DecryptedImageCache.isDecryptedImageCacheUri(message.pendingFileUri),
+                                    ),
                                     fileSizeBytes = message.fileSizes?.getOrNull(index),
                                     messageId = if (isImage) message.id else null,
                                     fileIndex = if (isImage) index else null,
+                                    clientMessageId = message.client_message_id,
                                     onFileClick = null,
                                     onImageClick = if (isImage) { { onImageClick?.invoke(message, index) } } else null,
                                     onImageBounds = if (isImage && imageKey != null && onImageBounds != null) {
@@ -504,6 +502,7 @@ fun MessageItem(
                                     } else null,
                                     isExpanded = isImage && expandedImageKey != null && expandedImageKey == imageKey && !isImageClosing,
                                     isAuthor = isAuthor,
+                                    messageLabel = message.content,
                                     modifier = if (isFirstImage && firstContentIsImage && isImage) {
                                         Modifier.padding(all = 2.dp)
                                     } else {
@@ -515,7 +514,12 @@ fun MessageItem(
                                 )
                             }
                         }
-                        if (message.content.isNotBlank() && !isCorrupted) {
+                        val hideFilenamePlaceholderCaption = message.pendingFileUri != null &&
+                            pendingIsImage &&
+                            message.files.isNullOrEmpty() &&
+                            message.pendingFilename != null &&
+                            message.content == message.pendingFilename
+                        if (message.content.isNotBlank() && !isCorrupted && !hideFilenamePlaceholderCaption) {
                             Text(
                                 text = message.content,
                                 style = MaterialTheme.typography.bodyMedium,
@@ -529,14 +533,14 @@ fun MessageItem(
                         }
 
                         // Timestamp, sending indicator, and edited indicator
-                        val isSendingText = message.id < 0 && message.uploadJobId == null
+                        val isPendingOutbound = message.id < 0 && message.files.isNullOrEmpty()
                         Row(
                             modifier = Modifier
                                 .padding(start = 12.dp, end = 12.dp, top = 4.dp, bottom = 8.dp),
                             horizontalArrangement = Arrangement.End,
                             verticalAlignment = Alignment.CenterVertically
                         ) {
-                            if (isSendingText) {
+                            if (isPendingOutbound) {
                                 CircularProgressIndicator(
                                     modifier = Modifier.size(12.dp),
                                     strokeWidth = 1.5.dp,
@@ -582,32 +586,3 @@ fun MessageItem(
     }
 }
 
-@ExperimentalTime
-private fun formatTime(timestamp: String): String {
-    return try {
-        Instant.parse(timestamp).toLocalDateTime(TimeZone.currentSystemDefault()).let {
-            "${
-                it.hour.toString().padStart(2, '0')
-            }:${
-                it.minute.toString().padStart(2, '0')
-            }"
-        }
-    } catch (_: Exception) {
-        // Fallback: try parsing without timezone if it fails
-        try {
-            val parts = timestamp.split("T")
-            if (parts.size == 2) {
-                val timePart = parts[1].split(".")[0]
-                if (timePart.length >= 5) {
-                    timePart.take(5) // Return HH:mm
-                } else {
-                    ""
-                }
-            } else {
-                ""
-            }
-        } catch (_: Exception) {
-            ""
-        }
-    }
-}

app/shared/src/commonMain/kotlin/ru/fromchat/ui/chat/MessageListDedup.kt

@@ -0,0 +1,80 @@
+package ru.fromchat.ui.chat
+
+import ru.fromchat.api.Message
+import ru.fromchat.api.parseMessageTimestampMillis
+
+/** One row per [Message.client_message_id]; prefers confirmed (id > 0) over optimistic. */
+internal fun dedupeMessagesByClientId(messages: List<Message>): List<Message> {
+    if (messages.size <= 1) return messages
+    val order = ArrayList<String>(messages.size)
+    val byKey = LinkedHashMap<String, Message>(messages.size)
+    for (msg in messages) {
+        val key = messageDedupeKey(msg)
+        if (!byKey.containsKey(key)) {
+            order.add(key)
+        }
+        val existing = byKey[key]
+        byKey[key] = when {
+            existing == null -> msg
+            else -> preferMessageForDedupe(existing, msg)
+        }
+    }
+    return order.mapNotNull { byKey[it] }
+}
+
+internal fun imageAttachmentKey(message: Message, fileIndex: Int): String {
+    val cid = message.client_message_id?.trim().orEmpty()
+    return if (cid.isNotEmpty()) "img_${cid}_$fileIndex" else "img_${message.id}_$fileIndex"
+}
+
+internal fun messageDedupeKey(msg: Message): String {
+    val cid = msg.client_message_id?.trim().orEmpty()
+    return if (cid.isNotEmpty()) "c:$cid" else "i:${msg.id}"
+}
+
+/** Drops optimistic rows already represented by a confirmed message (same client id or recent own attachment). */
+internal fun dropSupersededOptimisticMessages(
+    messages: List<Message>,
+    currentUserId: Int?,
+): List<Message> {
+    if (messages.none { it.id < 0 }) return messages
+    val confirmed = messages.filter { it.id > 0 }
+    val confirmedClientIds = confirmed.mapNotNull { it.client_message_id?.trim()?.takeIf { it.isNotEmpty() } }.toSet()
+    val self = currentUserId
+    return messages.filter { msg ->
+        if (msg.id >= 0) return@filter true
+        val cid = msg.client_message_id?.trim().orEmpty()
+        if (cid.isNotEmpty() && cid in confirmedClientIds) return@filter false
+        // In-flight uploads (file or image): keep until a confirmed row shares the same client id.
+        if (msg.pendingFileUri != null || !msg.uploadJobId.isNullOrBlank()) return@filter true
+        if (self == null || msg.user_id != self) return@filter true
+        val msgTime = parseMessageTimestampMillis(msg.timestamp)
+        val nearOwnConfirmed = confirmed.filter { it.user_id == self }.any { confirmedMsg ->
+            val confirmedTime = parseMessageTimestampMillis(confirmedMsg.timestamp)
+            msgTime != null && confirmedTime != null &&
+                kotlin.math.abs(msgTime - confirmedTime) <= NEAR_DUPLICATE_MS
+        }
+        if (!nearOwnConfirmed) return@filter true
+        val pendingIsAttachment = !msg.files.isNullOrEmpty()
+        val confirmedHasAttachment = confirmed.any { it.user_id == self && !it.files.isNullOrEmpty() }
+        when {
+            pendingIsAttachment && confirmedHasAttachment -> false
+            !pendingIsAttachment && !confirmedHasAttachment -> false
+            !pendingIsAttachment && confirmedHasAttachment -> false
+            else -> true
+        }
+    }
+}
+
+private const val NEAR_DUPLICATE_MS = 180_000L
+
+private fun preferMessageForDedupe(existing: Message, incoming: Message): Message {
+    val preferred = when {
+        incoming.id > 0 && existing.id < 0 -> incoming
+        existing.id > 0 && incoming.id < 0 -> existing
+        incoming.id >= existing.id -> incoming
+        else -> existing
+    }
+    val other = if (preferred === incoming) existing else incoming
+    return mergeMessageUiFields(preferred, other)
+}

app/shared/src/commonMain/kotlin/ru/fromchat/ui/chat/MessageUiMerge.kt

@@ -0,0 +1,71 @@
+package ru.fromchat.ui.chat
+
+import ru.fromchat.api.Message
+import ru.fromchat.api.db.aspectRatioFromDimensionPair
+import ru.fromchat.api.sortMessagesForChatDisplay
+import ru.fromchat.ui.chat.DecryptedImageCache
+
+/**
+ * SQLDelight rows omit optimistic attachment fields; merge DB snapshot with in-memory UI state.
+ */
+internal fun mergeDatabaseMessagesWithPanelState(
+    panelMessages: List<Message>,
+    dbMessages: List<Message>,
+): List<Message> {
+    val panelByClientId = panelMessages.mapNotNull { msg ->
+        msg.client_message_id?.trim()?.takeIf { it.isNotEmpty() }?.let { it to msg }
+    }.toMap()
+    val panelById = panelMessages.associateBy { it.id }
+
+    val mergedDb = dbMessages.map { db ->
+        val panel = db.client_message_id?.trim()?.takeIf { it.isNotEmpty() }?.let { panelByClientId[it] }
+            ?: panelById[db.id]
+        mergeMessageUiFields(db, panel)
+    }
+
+    val mergedClientIds = mergedDb.mapNotNull { it.client_message_id?.trim()?.takeIf { id -> id.isNotEmpty() } }.toSet()
+    val mergedIds = mergedDb.map { it.id }.toSet()
+    val extraPanel = panelMessages.filter { panel ->
+        val cid = panel.client_message_id?.trim()?.takeIf { it.isNotEmpty() }
+        when {
+            panel.id < 0 && cid != null && cid !in mergedClientIds -> true
+            panel.id > 0 && panel.id !in mergedIds && (cid.isNullOrEmpty() || cid !in mergedClientIds) -> true
+            else -> false
+        }
+    }
+
+    return dedupeMessagesByClientId(
+        dropSupersededOptimisticMessages(mergedDb + extraPanel, ru.fromchat.api.ApiClient.user?.id),
+    ).let { sortMessagesForChatDisplay(it) }
+}
+
+internal fun mergeMessageUiFields(db: Message, panel: Message?): Message {
+    if (panel == null) return db
+    val confirmed = db.id > 0
+    val localPreview = db.pendingFileUri?.takeIf { DecryptedImageCache.isDecryptedImageCacheUri(it) }
+        ?: panel.pendingFileUri?.takeIf { DecryptedImageCache.isDecryptedImageCacheUri(it) }
+    return db.copy(
+        pendingFileUri = when {
+            confirmed -> localPreview ?: db.pendingFileUri
+            else -> panel.pendingFileUri ?: db.pendingFileUri
+        },
+        pendingFilename = if (confirmed) null else panel.pendingFilename ?: db.pendingFilename,
+        pendingFileAspectRatio = if (confirmed) {
+            db.fileDimensions?.firstOrNull()?.let { (w, h) -> aspectRatioFromDimensionPair(w, h) }
+                ?: db.fileAspectRatios?.firstOrNull()
+                ?: db.pendingFileAspectRatio
+        } else {
+            panel.pendingFileAspectRatio ?: db.pendingFileAspectRatio
+        },
+        uploadJobId = if (confirmed) null else panel.uploadJobId ?: db.uploadJobId,
+        uploadProgress = if (confirmed) null else panel.uploadProgress ?: db.uploadProgress,
+        files = db.files ?: panel.files,
+        dmEnvelope = db.dmEnvelope ?: panel.dmEnvelope,
+        fileThumbnails = db.fileThumbnails ?: panel.fileThumbnails,
+        fileAspectRatios = db.fileAspectRatios ?: panel.fileAspectRatios,
+        fileSizes = db.fileSizes ?: panel.fileSizes,
+        fileDimensions = db.fileDimensions ?: panel.fileDimensions,
+        content = db.content.ifBlank { panel.content },
+        isContentCorrupted = panel.isContentCorrupted || db.isContentCorrupted,
+    )
+}

app/shared/src/commonMain/kotlin/ru/fromchat/ui/chat/OutboundImageStaging.kt

@@ -0,0 +1,60 @@
+package ru.fromchat.ui.chat
+
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import ru.fromchat.core.cache.CacheContext
+import ru.fromchat.core.cache.stageOutboundFileForUpload
+
+data class StagedOutboundPreview(
+    val stagedUri: String,
+    val aspectRatio: Float?,
+)
+
+/**
+ * Copy attachment into instance upload storage, seed disk + decoded bitmap caches.
+ * Upload worker reads the staged path; UI reads bitmap cache (no picker URI after revoke).
+ */
+suspend fun prepareOutboundImageForSend(
+    clientMessageId: String,
+    sourceUri: String,
+    optimisticMessageId: Int,
+    aspectRatio: Float?,
+): StagedOutboundPreview? = withContext(Dispatchers.Default) {
+    val instanceId = runCatching { CacheContext.requireActiveInstanceId() }.getOrNull() ?: return@withContext null
+    val staged = runCatching {
+        stageOutboundFileForUpload(instanceId, clientMessageId, sourceUri)
+    }.getOrNull() ?: return@withContext null
+    if (staged.sizeBytes <= 0L) return@withContext null
+
+    DecryptedImageCache.seedFromLocalFile(
+        messageId = optimisticMessageId,
+        fileIndex = 0,
+        localFileUri = staged.uri,
+        clientMessageId = clientMessageId,
+    )
+
+    val storageKey = DecryptedImageCache.storageKey(optimisticMessageId, 0, clientMessageId)
+    val decodeTarget = previewSeedDecodeSize(aspectRatio)
+    LocalDecodedImageCache.loadFull(storageKey, staged.uri, decodeTarget)
+
+    StagedOutboundPreview(stagedUri = staged.uri, aspectRatio = aspectRatio)
+}
+
+/** High-quality seed decode before the tile is measured (refined when laid out). */
+internal fun previewSeedDecodeSize(aspectRatio: Float?): ChatPreviewDecodeSize {
+    val longEdge = 1440
+    val ratio = aspectRatio?.takeIf { it.isFinite() && it > 0f } ?: 1f
+    return if (ratio >= 1f) {
+        ChatPreviewDecodeSize(longEdge, (longEdge / ratio).toInt().coerceAtLeast(1))
+    } else {
+        ChatPreviewDecodeSize((longEdge * ratio).toInt().coerceAtLeast(1), longEdge)
+    }
+}
+
+suspend fun clearOutboundImageCaches(clientMessageId: String, optimisticMessageId: Int) {
+    withContext(Dispatchers.Default) {
+        DecryptedImageCache.invalidateForClientMessage(clientMessageId)
+        val storageKey = DecryptedImageCache.storageKey(optimisticMessageId, 0, clientMessageId)
+        LocalDecodedImageCache.evict(storageKey)
+    }
+}

app/shared/src/commonMain/kotlin/ru/fromchat/ui/chat/PublicChatPanel.kt

@@ -16,6 +16,10 @@ import ru.fromchat.api.TypingUpdateData
 import ru.fromchat.api.WebSocketMessage
 import ru.fromchat.api.WebSocketUpdatesData
 import ru.fromchat.api.db.MessageCacheStore
+import ru.fromchat.api.db.MessageRepository
+import ru.fromchat.api.db.conversationIdForGroup
+import ru.fromchat.api.db.GENERAL_PUBLIC_GROUP_ID
+import ru.fromchat.api.outbox.OutgoingMessageCoordinator
 import ru.fromchat.core.Logger
 
 class PublicChatPanel(
@@ -142,7 +146,15 @@ class PublicChatPanel(
     }
 
     override suspend fun sendMessage(content: String, replyToId: Int?, clientMessageId: String?) {
-        ApiClient.sendMessage(content, replyToId, clientMessageId)
+        val cid = clientMessageId?.trim().orEmpty()
+        if (cid.isEmpty()) return
+        val optimistic = _state.messages.find { it.client_message_id == cid } ?: return
+        OutgoingMessageCoordinator.enqueuePublicMessage(
+            content = content,
+            replyToId = replyToId,
+            clientMessageId = cid,
+            optimisticMessage = optimistic,
+        )
     }
 
     override suspend fun persistOptimisticMessage(message: Message) {
@@ -307,7 +319,7 @@ class PublicChatPanel(
                 DecryptedImageCache.invalidateForMessage(deletedData.message_id)
                 removeMessage(deletedData.message_id)
                 withContext(Dispatchers.Default) {
-                    MessageCacheStore.markMessageDeleted("public", deletedData.message_id)
+                    MessageRepository.markPublicMessageDeleted(deletedData.message_id)
                     MessageCacheStore.replacePublicMessages(_state.messages)
                 }
             }
@@ -387,4 +399,6 @@ class PublicChatPanel(
     override fun showCallButton(): Boolean = false
 
     override fun getTypingHandler(): TypingHandler = typingHandler
+
+    override fun outboxConversationId(): String = conversationIdForGroup(GENERAL_PUBLIC_GROUP_ID)
 }

app/shared/src/commonMain/kotlin/ru/fromchat/ui/chat/PublicChatPanelCache.kt

@@ -3,6 +3,7 @@ package ru.fromchat.ui.chat
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.SupervisorJob
+import ru.fromchat.core.cache.CacheContext
 
 /**
  * Single retained [PublicChatPanel] for the app session (same idea as [ru.fromchat.ui.dm.DmPanelCache]).
@@ -23,6 +24,14 @@ object PublicChatPanelCache {
     private var cachedPanelKey: String? = null
     private var cachedDisplayTitle: String? = null
     private var cachedUserId: Int? = null
+    private var cachedInstanceId: String = ""
+
+    fun onActiveInstanceChanged(instanceId: String) {
+        if (cachedInstanceId.isNotEmpty() && cachedInstanceId != instanceId) {
+            clear()
+        }
+        cachedInstanceId = instanceId
+    }
 
     private fun ensureScope() {
         if (!supervisorJob.isActive) {
@@ -36,10 +45,16 @@ object PublicChatPanelCache {
      */
     fun getOrCreateGeneralChat(displayTitle: String, currentUserId: Int?): PublicChatPanel {
         ensureScope()
+        val instanceId = CacheContext.activeInstanceId.value.trim()
+        if (instanceId.isNotEmpty() && cachedInstanceId.isNotEmpty() && cachedInstanceId != instanceId) {
+            clear()
+        }
+        if (instanceId.isNotEmpty()) cachedInstanceId = instanceId
         if (
             panel != null &&
             cachedPanelKey == GeneralPublicPanelKey &&
-            cachedUserId == currentUserId
+            cachedUserId == currentUserId &&
+            (instanceId.isEmpty() || cachedInstanceId == instanceId)
         ) {
             if (cachedDisplayTitle != displayTitle) {
                 cachedDisplayTitle = displayTitle

app/shared/src/commonMain/kotlin/ru/fromchat/ui/chat/PublicChatScreen.kt

@@ -5,10 +5,14 @@ import androidx.compose.animation.SharedTransitionScope
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.DisposableEffect
 import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
 import androidx.compose.runtime.remember
 import org.jetbrains.compose.resources.stringResource
 import ru.fromchat.Res
 import ru.fromchat.api.ApiClient
+import ru.fromchat.api.db.MessageRepository
+import ru.fromchat.core.cache.CacheContext
 import ru.fromchat.ui.isPublicChatVisible
 import ru.fromchat.*
 
@@ -26,12 +30,21 @@ fun PublicChatScreen(
         PublicChatPanelCache.getOrCreateGeneralChat(publicChatTitle, currentUserId)
     }
 
+    val activeInstanceId by CacheContext.activeInstanceId.collectAsState()
+
     LaunchedEffect(panel) {
         if (panel.getState().messages.isEmpty()) {
             panel.loadMessages()
         }
     }
 
+    LaunchedEffect(panel, activeInstanceId) {
+        if (activeInstanceId.isBlank()) return@LaunchedEffect
+        MessageRepository.observePublicMessages().collect { rows ->
+            panel.syncMessagesFromDatabase(rows)
+        }
+    }
+
     // Track visibility for notifications
     DisposableEffect(Unit) {
         isPublicChatVisible = true

app/shared/src/commonMain/kotlin/ru/fromchat/ui/dm/DmNav.kt

@@ -4,8 +4,10 @@ import androidx.compose.animation.AnimatedVisibilityScope
 import androidx.compose.animation.SharedTransitionScope
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
 import androidx.compose.runtime.remember
-import androidx.compose.runtime.rememberCoroutineScope
+import ru.fromchat.core.cache.CacheContext
 import androidx.compose.ui.Modifier
 import androidx.navigation.NavController
 import ru.fromchat.ui.HapticFeedbackEvent
@@ -39,8 +41,8 @@ fun DmChatRoute(
     animatedVisibilityScope: AnimatedVisibilityScope,
     modifier: Modifier = Modifier,
 ) {
-    val scope = rememberCoroutineScope()
-    val panel = remember(otherUserId, scope) { DmPanelCache.getOrCreate(otherUserId, scope) }
+    val activeInstanceId by CacheContext.activeInstanceId.collectAsState()
+    val panel = remember(otherUserId, activeInstanceId) { DmPanelCache.getOrCreate(otherUserId) }
     val haptic = rememberHapticFeedback()
     val sharedAvatarKey = remember(otherUserId) { "$DM_AVATAR_KEY_PREFIX$otherUserId" }
 
@@ -66,8 +68,8 @@ fun DmProfileRoute(
     animatedVisibilityScope: AnimatedVisibilityScope,
     modifier: Modifier = Modifier,
 ) {
-    val scope = rememberCoroutineScope()
-    val panel = remember(otherUserId, scope) { DmPanelCache.getOrCreate(otherUserId, scope) }
+    val activeInstanceId by CacheContext.activeInstanceId.collectAsState()
+    val panel = remember(otherUserId, activeInstanceId) { DmPanelCache.getOrCreate(otherUserId) }
     val haptic = rememberHapticFeedback()
     val sharedAvatarKey = remember(otherUserId) { "$DM_AVATAR_KEY_PREFIX$otherUserId" }
     val stateSnapshot = panel.getState()

app/shared/src/commonMain/kotlin/ru/fromchat/ui/dm/DmPanel.kt

@@ -6,6 +6,7 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.sync.Mutex
 import kotlinx.coroutines.sync.withLock
+import kotlinx.coroutines.withContext
 import kotlinx.serialization.json.Json
 import kotlinx.serialization.json.JsonArray
 import kotlinx.serialization.json.JsonElement
@@ -15,10 +16,19 @@ import kotlinx.serialization.json.jsonObject
 import kotlinx.serialization.json.jsonPrimitive
 import ru.fromchat.api.ApiClient
 import ru.fromchat.api.DmEnvelope
+import ru.fromchat.api.DmDeletedData
 import ru.fromchat.api.Message
+import ru.fromchat.api.sortMessagesForChatDisplay
 import ru.fromchat.api.ProfileCache
 import ru.fromchat.api.WebSocketMessage
 import ru.fromchat.api.db.MessageCacheStore
+import ru.fromchat.api.AttachmentDownloadNotifier
+import ru.fromchat.api.AttachmentDownloadProgress
+import ru.fromchat.api.db.parseDmMessageContent
+import ru.fromchat.api.db.resolveLocalPreviewUri
+import ru.fromchat.api.db.MessageRepository
+import ru.fromchat.api.db.conversationIdForDm
+import ru.fromchat.api.outbox.OutgoingMessageCoordinator
 import ru.fromchat.api.visibleDisplayName
 import ru.fromchat.core.Logger
 import ru.fromchat.core.config.Config
@@ -30,6 +40,11 @@ import ru.fromchat.ui.chat.ChatPanel
 import ru.fromchat.ui.chat.DecryptedImageCache
 import ru.fromchat.ui.chat.DmTypingHandler
 import ru.fromchat.ui.chat.TypingHandler
+import ru.fromchat.ui.chat.dedupeMessagesByClientId
+import ru.fromchat.ui.chat.dropSupersededOptimisticMessages
+import ru.fromchat.ui.chat.imageAspectRatioForMessage
+import ru.fromchat.ui.chat.AttachmentMediaLog
+import ru.fromchat.ui.chat.isImageFilename
 
 class DmPanel(
     private val otherUserId: Int,
@@ -74,6 +89,22 @@ class DmPanel(
                 updateState { it.copy(typingUsers = users) }
             }
         }
+        coroutineScope.launch(Dispatchers.Default) {
+            AttachmentDownloadNotifier.progressFlow.collect { event ->
+                if (event !is AttachmentDownloadProgress.Success || event.messageId <= 0) return@collect
+                val uri = DecryptedImageCache.getUriForStorageKey(event.storageKey) ?: return@collect
+                withContext(Dispatchers.Main) {
+                    updateMessage(event.messageId) { msg ->
+                        msg.copy(pendingFileUri = uri)
+                    }
+                }
+                MessageCacheStore.patchDmMessageLocalPreview(
+                    otherUserId = otherUserId,
+                    messageId = event.messageId,
+                    localPreviewUri = uri,
+                )
+            }
+        }
         coroutineScope.launch(Dispatchers.Default) {
             runCatching {
                 ApiClient.getProfileById(otherUserId)
@@ -109,11 +140,15 @@ class DmPanel(
     }
 
     override suspend fun sendMessage(content: String, replyToId: Int?, clientMessageId: String?) {
-        ApiClient.sendDm(
+        val cid = clientMessageId?.trim().orEmpty()
+        if (cid.isEmpty()) return
+        val optimistic = _state.messages.find { it.client_message_id == cid } ?: return
+        OutgoingMessageCoordinator.enqueueDmMessage(
             recipientId = otherUserId,
             plaintext = content,
-            clientMessageId = clientMessageId,
-            replyToId = replyToId
+            clientMessageId = cid,
+            replyToId = replyToId,
+            optimisticMessage = optimistic,
         )
     }
 
@@ -128,11 +163,15 @@ class DmPanel(
 
     override suspend fun onOptimisticMessageConfirmed(clientMessageId: String, confirmed: Message) {
         MessageCacheStore.confirmDmMessage(otherUserId, clientMessageId, confirmed)
+        OutgoingMessageCoordinator.clearAttachmentOutboxAfterAck(clientMessageId)
     }
 
     override suspend fun loadMessages() {
         setLoading(true)
         try {
+            OutgoingMessageCoordinator.pruneStaleAttachmentOutboxForInstance(
+                ru.fromchat.core.cache.CacheContext.requireActiveInstanceId(),
+            )
             val cached = runCatching { MessageCacheStore.loadDmMessages(otherUserId) }.getOrDefault(emptyList())
             if (cached.isNotEmpty()) {
                 clearMessages()
@@ -142,6 +181,7 @@ class DmPanel(
             val historyResult = runCatching { ApiClient.getDmHistory(otherUserId) }
             if (historyResult.isSuccess) {
                 val response = historyResult.getOrNull() ?: return
+                val optimisticSnapshot = snapshotPendingOptimisticMessages()
                 clearMessages()
                 val decryptedForLog = mutableListOf<Pair<Int, String>>()
                 val messages = response.messages.map { envelope ->
@@ -160,10 +200,18 @@ class DmPanel(
                     } else msg
                 }
                 addMessages(messagesWithReplies)
+                restorePendingOptimisticMessages(optimisticSnapshot)
+                updateState { state ->
+                    val cleaned = dedupeMessagesByClientId(
+                        dropSupersededOptimisticMessages(state.messages, currentUserId),
+                    )
+                    if (cleaned == state.messages) state else state.copy(messages = cleaned)
+                }
                 setHasMoreMessages(false)
 
                 // Persist the most recent DM messages for offline use.
-                MessageCacheStore.replaceDmMessages(otherUserId, messagesWithReplies)
+                val mergedForCache = _state.messages
+                MessageCacheStore.replaceDmMessages(otherUserId, mergedForCache)
             } else {
                 val error = historyResult.exceptionOrNull()
                 Logger.e("DmPanel", "Failed to load DM history: ${error?.message}", error)
@@ -186,6 +234,7 @@ class DmPanel(
         when (message.type) {
             "dmNew" -> message.data?.let { processEnvelope(it) }
             "dmEdited" -> message.data?.let { processEditedEnvelope(it) }
+            "dmDeleted" -> message.data?.let { processDeletedEnvelope(it) }
             "dmTyping" -> message.data?.let { data ->
                 val obj = data.jsonObject
                 val userId = obj["userId"]?.jsonPrimitive?.content?.toIntOrNull()
@@ -205,6 +254,7 @@ class DmPanel(
                     when (type) {
                         "dmNew" -> obj["data"]?.let { processEnvelope(it) }
                         "dmEdited" -> obj["data"]?.let { processEditedEnvelope(it) }
+                        "dmDeleted" -> obj["data"]?.let { processDeletedEnvelope(it) }
                         "dmTyping" -> obj["data"]?.let { data ->
                             val dataObj = data.jsonObject
                             val userId = dataObj["userId"]?.jsonPrimitive?.content?.toIntOrNull()
@@ -230,10 +280,26 @@ class DmPanel(
         if (envelope.senderId != otherUserId && envelope.recipientId != otherUserId) return
         scope.launch(Dispatchers.Default) {
             dmEnvelopeMutex.withLock {
-                val alreadyExists = _state.messages.any { it.id == envelope.id }
+                val cid = envelope.clientMessageId?.trim().orEmpty()
                 val outcome = decryptDmEnvelopeForUi(envelope)
 
-                if (alreadyExists) return@withLock
+                if (envelope.senderId == currentUserId && cid.isNotEmpty()) {
+                    val hasOptimistic = _state.messages.any { message ->
+                        message.user_id == currentUserId &&
+                            (message.client_message_id == cid || message.uploadJobId == cid)
+                    }
+                    if (hasOptimistic) {
+                        mergeConfirmedOwnMessage(envelope, outcome.plaintext, outcome.isCorrupted)
+                        if (envelope.replyToId != null) {
+                            val replyTo = _state.messages.find { it.id == envelope.replyToId }
+                            updateMessage(envelope.id) { it.copy(reply_to = replyTo) }
+                        }
+                        MessageCacheStore.replaceDmMessages(otherUserId, _state.messages)
+                        return@withLock
+                    }
+                }
+
+                if (_state.messages.any { it.id == envelope.id }) return@withLock
 
                 if (envelope.senderId == currentUserId) {
                     mergeConfirmedOwnMessage(envelope, outcome.plaintext, outcome.isCorrupted)
@@ -245,7 +311,6 @@ class DmPanel(
                     updateMessage(envelope.id) { it.copy(reply_to = replyTo) }
                 }
 
-                // Persist updated DM thread to cache
                 MessageCacheStore.replaceDmMessages(otherUserId, _state.messages)
             }
         }
@@ -254,65 +319,95 @@ class DmPanel(
     private fun mergeConfirmedOwnMessage(envelope: DmEnvelope, plaintext: String, isContentCorrupted: Boolean) {
         val confirmed = createMessage(envelope, plaintext, isContentCorrupted)
         val hasAttachments = !envelope.files.isNullOrEmpty()
+        val cid = envelope.clientMessageId?.trim().orEmpty()
+        val stateSourceBeforeMerge = _state.messages.firstOrNull { message ->
+            message.user_id == currentUserId &&
+                cid.isNotEmpty() &&
+                (message.client_message_id == cid || message.uploadJobId == cid)
+        }
+        val localUri = stateSourceBeforeMerge?.pendingFileUri
+        val dmFile = envelope.files?.firstOrNull()
+        val isImageAttachment = dmFile?.let { isImageFilename(it.name) } == true
+        val aspect = imageAspectRatioForMessage(
+            fileAspectRatios = confirmed.fileAspectRatios,
+            fileDimensions = confirmed.fileDimensions ?: stateSourceBeforeMerge?.fileDimensions,
+            pendingFileAspectRatio = stateSourceBeforeMerge?.pendingFileAspectRatio,
+            fileIndex = 0,
+            confirmed = true,
+        )
 
-        updateState { currentState ->
-            val existingRealIndex = currentState.messages.indexOfFirst { it.id == envelope.id }
-            val byClientIdIndex = currentState.messages.indexOfFirst { message ->
-                message.id < 0 &&
-                    message.user_id == currentUserId &&
-                    envelope.clientMessageId != null &&
-                    (message.client_message_id == envelope.clientMessageId || message.uploadJobId == envelope.clientMessageId)
+        scope.launch(Dispatchers.Default) {
+            if (isImageAttachment && localUri != null && dmFile != null) {
+                DecryptedImageCache.seedFromLocalFile(
+                    messageId = envelope.id,
+                    fileIndex = 0,
+                    localFileUri = localUri,
+                    clientMessageId = cid,
+                )
+                DecryptedImageCache.ensureDiskAliasForMessageId(
+                    messageId = envelope.id,
+                    fileIndex = 0,
+                    clientMessageId = cid,
+                )
             }
-            val exactOptimisticIndex = currentState.messages.indexOfFirst { message ->
-                message.user_id == currentUserId &&
-                    message.pendingFileUri != null &&
-                    envelope.clientMessageId != null &&
-                    (message.client_message_id == envelope.clientMessageId || message.uploadJobId == envelope.clientMessageId)
-            }
-            val optimisticIndex = when {
-                byClientIdIndex >= 0 -> byClientIdIndex
-                exactOptimisticIndex >= 0 -> exactOptimisticIndex
-                else -> currentState.messages.indexOfFirst { message ->
-                    message.id < 0 &&
-                        message.user_id == currentUserId &&
-                        (message.pendingFileUri != null) == hasAttachments
-                }
-            }
-
-            val stateSource = when {
-                optimisticIndex >= 0 -> currentState.messages[optimisticIndex]
-                existingRealIndex >= 0 -> currentState.messages[existingRealIndex]
-                else -> null
-            }
-
-            val merged = confirmed.copy(
-                uploadJobId = stateSource?.uploadJobId,
-                pendingFileUri = stateSource?.pendingFileUri,
-                pendingFilename = stateSource?.pendingFilename,
-                pendingFileAspectRatio = stateSource?.pendingFileAspectRatio,
-                uploadProgress = stateSource?.uploadProgress
+            val localPreviewUri = resolveLocalPreviewUri(
+                confirmed.copy(
+                    client_message_id = cid.ifEmpty { confirmed.client_message_id },
+                    pendingFileUri = localUri ?: confirmed.pendingFileUri,
+                ),
             )
 
-            val newMessages = when {
-                optimisticIndex >= 0 -> {
-                    currentState.messages.mapIndexedNotNull { index, message ->
-                        when {
-                            index == optimisticIndex -> merged
-                            message.id == envelope.id -> null
-                            else -> message
+            val merged = confirmed.copy(
+                uploadJobId = null,
+                uploadProgress = null,
+                pendingFileUri = if (isImageAttachment) localPreviewUri ?: localUri else null,
+                pendingFilename = null,
+                pendingFileAspectRatio = aspect,
+                fileAspectRatios = confirmed.fileAspectRatios ?: aspect?.let { listOf(it) },
+                fileDimensions = confirmed.fileDimensions ?: stateSourceBeforeMerge?.fileDimensions,
+            )
+            val mergedForPersistence = merged.copy(pendingFilename = null)
+            AttachmentMediaLog.persist(
+                "merge_confirmed",
+                "msgId" to envelope.id,
+                "clientId" to cid,
+                "localPreview" to (merged.pendingFileUri?.take(64) ?: "null"),
+                "aspect" to aspect,
+            )
+
+            withContext(Dispatchers.Main) {
+                updateState { currentState ->
+                    val optimisticIndex = currentState.messages.indexOfFirst { message ->
+                        message.user_id == currentUserId &&
+                            cid.isNotEmpty() &&
+                            (message.client_message_id == cid || message.uploadJobId == cid)
+                    }
+                    val existingRealIndex = currentState.messages.indexOfFirst { it.id == envelope.id }
+                    val newMessages = when {
+                        optimisticIndex >= 0 -> {
+                            currentState.messages.mapIndexedNotNull { index, message ->
+                                when {
+                                    index == optimisticIndex -> merged
+                                    message.id == envelope.id -> null
+                                    else -> message
+                                }
+                            }
                         }
+                        existingRealIndex >= 0 -> {
+                            currentState.messages.mapIndexed { index, message ->
+                                if (index == existingRealIndex) merged else message
+                            }
+                        }
+                        else -> currentState.messages + merged
                     }
+                    currentState.copy(messages = dedupeMessagesByClientId(newMessages))
                 }
-
-                existingRealIndex >= 0 -> {
-                    currentState.messages.mapIndexed { index, message ->
-                        if (index == existingRealIndex) merged else message
-                    }
-                }
-
-                else -> currentState.messages + merged
             }
-            currentState.copy(messages = newMessages)
+
+            if (cid.isNotEmpty()) {
+                MessageCacheStore.confirmDmMessage(otherUserId, cid, mergedForPersistence)
+                OutgoingMessageCoordinator.clearAttachmentOutboxAfterAck(cid)
+            }
         }
     }
 
@@ -322,15 +417,22 @@ class DmPanel(
         }.getOrNull() ?: return
         if (envelope.senderId != otherUserId && envelope.recipientId != otherUserId) return
         scope.launch(Dispatchers.Default) {
-            DecryptedImageCache.invalidateForMessage(envelope.id)
+            val previous = _state.messages.find { it.id == envelope.id }
+            val filesChanged = previous?.files != envelope.files
+            if (filesChanged) {
+                DecryptedImageCache.invalidateForMessage(envelope.id)
+                envelope.clientMessageId?.trim()?.takeIf { it.isNotEmpty() }?.let {
+                    DecryptedImageCache.invalidateForClientMessage(it)
+                }
+            }
             val outcome = decryptDmEnvelopeForUi(envelope)
-            val dec = parseDecryptedContent(outcome.plaintext)
+            val dec = parseDmMessageContent(outcome.plaintext)
             updateMessage(envelope.id) {
                 it.copy(
                     content = dec.text,
                     is_edited = true,
-                    fileThumbnails = dec.thumbnails ?: it.fileThumbnails,
-                    fileAspectRatios = dec.aspectRatios ?: it.fileAspectRatios,
+                    fileThumbnails = dec.fileThumbnails ?: it.fileThumbnails,
+                    fileAspectRatios = dec.fileAspectRatios ?: it.fileAspectRatios,
                     fileSizes = dec.fileSizes ?: it.fileSizes,
                     fileDimensions = dec.fileDimensions ?: it.fileDimensions,
                     isContentCorrupted = outcome.isCorrupted
@@ -342,43 +444,8 @@ class DmPanel(
         }
     }
 
-    private data class DecryptedContent(
-        val text: String,
-        val thumbnails: List<String>?,
-        val aspectRatios: List<Float>?,
-        val fileSizes: List<Long>?,
-        val fileDimensions: List<Pair<Int, Int>>?
-    )
-
-    private fun parseDecryptedContent(plaintext: String): DecryptedContent {
-        return runCatching {
-            val obj = json.parseToJsonElement(plaintext).jsonObject
-            val text = obj["text"]?.jsonPrimitive?.content ?: return@runCatching DecryptedContent(plaintext, null, null, null, null)
-            val thumbArr = obj["fileThumbnails"]?.jsonArray ?: return@runCatching DecryptedContent(text, null, null, null, null)
-            val thumbnails = thumbArr.map { it.jsonPrimitive.content }
-            val arArr = obj["fileAspectRatios"]?.jsonArray
-            val parsed = arArr?.mapNotNull { elem ->
-                val a = elem as? JsonArray ?: return@mapNotNull null
-                if (a.size == 2) {
-                    val w = (a.getOrNull(0) as? JsonPrimitive)?.content?.toIntOrNull()
-                    val h = (a.getOrNull(1) as? JsonPrimitive)?.content?.toIntOrNull()
-                    if (w != null && h != null && h > 0) Triple(w, h, w.toFloat() / h) else null
-                } else null
-            }?.takeIf { it.size == thumbnails.size }
-            val aspectRatios = parsed?.map { it.third }
-            val fileDimensions = parsed?.map { it.first to it.second }
-            val sizesArr = obj["fileSizes"]?.jsonArray
-            val fileSizes = sizesArr?.mapNotNull { (it as? JsonPrimitive)?.content?.toLongOrNull() }?.takeIf { it.size == thumbnails.size }
-            Logger.d("DmPanel", "parseDecryptedContent: thumbnails=${thumbnails.size}, aspectRatios=${aspectRatios?.size}, fileSizes=${fileSizes?.size}")
-            DecryptedContent(text, thumbnails.ifEmpty { null }, aspectRatios, fileSizes, fileDimensions)
-        }.getOrElse {
-            Logger.d("DmPanel", "parseDecryptedContent: parse failed, using plaintext fallback")
-            DecryptedContent(plaintext, null, null, null, null)
-        }
-    }
-
     private fun createMessage(envelope: DmEnvelope, plaintext: String, isContentCorrupted: Boolean): Message {
-        val dec = parseDecryptedContent(plaintext)
+        val dec = parseDmMessageContent(plaintext)
         val username = if (envelope.senderId == currentUserId) {
             "You"
         } else {
@@ -399,8 +466,8 @@ class DmPanel(
             reactions = null,
             files = envelope.files,
             dmEnvelope = envelope,
-            fileThumbnails = dec.thumbnails,
-            fileAspectRatios = dec.aspectRatios,
+            fileThumbnails = dec.fileThumbnails,
+            fileAspectRatios = dec.fileAspectRatios,
             fileSizes = dec.fileSizes,
             fileDimensions = dec.fileDimensions,
             isContentCorrupted = isContentCorrupted
@@ -417,7 +484,43 @@ class DmPanel(
         }
     }
 
-    override suspend fun handleDeleteMessage(messageId: Int) {}
+    override suspend fun handleDeleteMessage(messageId: Int) {
+        if (messageId < 0) {
+            val queued = _state.messages.find { it.id == messageId } ?: return
+            cancelQueuedMessage(queued)
+            return
+        }
+        val clientId = _state.messages.find { it.id == messageId }?.client_message_id
+        deleteMessageImmediately(messageId)
+        DecryptedImageCache.invalidateForMessage(messageId)
+        clientId?.trim()?.takeIf { it.isNotEmpty() }?.let {
+            DecryptedImageCache.invalidateForClientMessage(it)
+        }
+        runCatching { ApiClient.deleteDm(messageId, otherUserId) }
+        withContext(Dispatchers.Default) {
+            MessageRepository.deleteDmMessageById(otherUserId, messageId)
+        }
+    }
+
+    private fun processDeletedEnvelope(element: JsonElement) {
+        val data = runCatching {
+            json.decodeFromJsonElement(DmDeletedData.serializer(), element)
+        }.getOrNull() ?: return
+        val involvesPeer =
+            data.senderId == otherUserId ||
+                data.recipientId == otherUserId ||
+                data.senderId == currentUserId
+        if (!involvesPeer) return
+        scope.launch(Dispatchers.Default) {
+            val clientId = _state.messages.find { it.id == data.id }?.client_message_id
+            DecryptedImageCache.invalidateForMessage(data.id)
+            clientId?.trim()?.takeIf { it.isNotEmpty() }?.let {
+                DecryptedImageCache.invalidateForClientMessage(it)
+            }
+            deleteMessageImmediately(data.id)
+            MessageRepository.deleteDmMessageById(otherUserId, data.id)
+        }
+    }
 
     override fun showCallButton(): Boolean = Config.callsEnabled
 
@@ -427,4 +530,6 @@ class DmPanel(
 
     override val showUsernamesInMessages: Boolean
         get() = false
+
+    override fun outboxConversationId(): String = conversationIdForDm(otherUserId)
 }

app/shared/src/commonMain/kotlin/ru/fromchat/ui/dm/DmPanelCache.kt

@@ -1,23 +1,50 @@
 package ru.fromchat.ui.dm
 
 import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.SupervisorJob
 import ru.fromchat.api.ApiClient
+import ru.fromchat.core.cache.CacheContext
 
 /**
  * Cache of DM panels by otherUserId so that when navigating back from profile
  * we reuse the same panel and don't reload messages.
+ *
+ * Uses a [SupervisorJob] scope instead of [androidx.compose.runtime.rememberCoroutineScope]
+ * so [ru.fromchat.ui.chat.ChatPanel] state callbacks keep working after the composable is left.
  */
 object DmPanelCache {
-    private val panels = mutableMapOf<Int, DmPanel>()
+    private var supervisorJob = SupervisorJob()
+    private var panelScope: CoroutineScope = CoroutineScope(supervisorJob + Dispatchers.Main.immediate)
 
-    fun getOrCreate(
-        otherUserId: Int,
-        scope: CoroutineScope
-    ): DmPanel {
+    private val panels = mutableMapOf<Int, DmPanel>()
+    private var cachedInstanceId: String = ""
+
+    fun onActiveInstanceChanged(instanceId: String) {
+        if (cachedInstanceId.isNotEmpty() && cachedInstanceId != instanceId) {
+            clearAll()
+        }
+        cachedInstanceId = instanceId
+    }
+
+    private fun ensureScope() {
+        if (!supervisorJob.isActive) {
+            supervisorJob = SupervisorJob()
+            panelScope = CoroutineScope(supervisorJob + Dispatchers.Main.immediate)
+        }
+    }
+
+    fun getOrCreate(otherUserId: Int): DmPanel {
+        ensureScope()
+        val instanceId = CacheContext.activeInstanceId.value.trim()
+        if (instanceId.isNotEmpty() && cachedInstanceId.isNotEmpty() && cachedInstanceId != instanceId) {
+            clearAll()
+        }
+        if (instanceId.isNotEmpty()) cachedInstanceId = instanceId
         return panels.getOrPut(otherUserId) {
             DmPanel(
                 otherUserId = otherUserId,
-                coroutineScope = scope,
+                coroutineScope = panelScope,
                 currentUserId = ApiClient.user?.id
             )
         }
@@ -30,5 +57,6 @@ object DmPanelCache {
     fun clearAll() {
         panels.values.forEach { it.destroy() }
         panels.clear()
+        supervisorJob.cancel()
     }
 }

app/shared/src/commonMain/kotlin/ru/fromchat/ui/dm/DmScreen.kt

@@ -5,9 +5,17 @@ import androidx.compose.animation.SharedTransitionScope
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.geometry.Rect
 import ru.fromchat.api.ApiClient
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import ru.fromchat.api.db.MessageRepository
+import ru.fromchat.api.outbox.OutgoingMessageCoordinator
+import ru.fromchat.api.outbox.scheduleOutboxProcessing
+import ru.fromchat.core.cache.CacheContext
 import ru.fromchat.ui.chat.ChatScreen
 
 @Composable
@@ -24,13 +32,33 @@ fun DmScreen(
     sharedAvatarKey: Any? = null
 ) {
     val currentUserId = ApiClient.user?.id
+    val activeInstanceId by CacheContext.activeInstanceId.collectAsState()
+    val otherUserId = panel.getState().profileUserId
 
-    LaunchedEffect(panel) {
-        if (panel.getState().messages.isEmpty()) {
+    LaunchedEffect(panel, otherUserId) {
+        if (otherUserId != null && otherUserId > 0) {
             panel.loadMessages()
         }
     }
 
+    LaunchedEffect(activeInstanceId, otherUserId) {
+        val peerId = otherUserId ?: return@LaunchedEffect
+        val instanceId = activeInstanceId.trim()
+        if (instanceId.isBlank() || peerId <= 0) return@LaunchedEffect
+        scheduleOutboxProcessing(instanceId)
+        withContext(Dispatchers.Default) {
+            OutgoingMessageCoordinator.drainOutboxForInstance(instanceId)
+        }
+    }
+
+    LaunchedEffect(panel, activeInstanceId, otherUserId) {
+        val peerId = otherUserId ?: return@LaunchedEffect
+        if (activeInstanceId.isBlank() || peerId <= 0) return@LaunchedEffect
+        MessageRepository.observeDmMessages(peerId).collect { rows ->
+            panel.syncMessagesFromDatabase(rows)
+        }
+    }
+
     ChatScreen(
         panel = panel,
         currentUserId = currentUserId,

app/shared/src/commonMain/kotlin/ru/fromchat/ui/main/ChatsTab.kt

@@ -64,6 +64,9 @@ import ru.fromchat.api.UserStatus
 import ru.fromchat.api.UserStatusStore
 import ru.fromchat.api.db.CachedConversation
 import ru.fromchat.api.db.MessageCacheStore
+import ru.fromchat.api.db.MessageRepository
+import ru.fromchat.core.cache.CacheContext
+import ru.fromchat.core.config.Config
 import ru.fromchat.app_name
 import ru.fromchat.chat_last_mesaage
 import ru.fromchat.net.NetworkConnectivity
@@ -172,25 +175,25 @@ fun ChatsTab(
         }
     }
 
-    LaunchedEffect(Unit) {
-        // Load cached DM conversations first for instant offline display.
-        runCatching {
-            dmConversations = MessageCacheStore.loadCachedDmConversations()
-        }
+    val serverConfig by Config.serverConfig.collectAsState()
+    val activeInstanceId by CacheContext.activeInstanceId.collectAsState()
 
+    LaunchedEffect(serverConfig, activeInstanceId) {
+        if (activeInstanceId.isBlank()) return@LaunchedEffect
         runCatching {
-            val last = MessageCacheStore.loadRecentPublicMessages(1).lastOrNull()
+            dmConversations = MessageRepository.loadCachedDmConversations()
+        }
+        runCatching {
+            val last = MessageRepository.loadRecentPublicMessages(1).lastOrNull()
             publicLastMessagePreview = last?.content?.trim()?.takeIf { it.isNotEmpty() }
         }
-
-        // Then refresh from network and update cache + state.
         runCatching {
             ApiClient.getDmConversations()
         }.onSuccess { conversations ->
             runCatching {
                 conversations.forEach { ProfileCache.mergeFromDmUser(it.user) }
-                MessageCacheStore.replaceDmConversations(conversations)
-                dmConversations = MessageCacheStore.loadCachedDmConversations()
+                MessageRepository.replaceDmConversations(conversations)
+                dmConversations = MessageRepository.loadCachedDmConversations()
             }
         }
     }

app/shared/src/commonMain/kotlin/ru/fromchat/ui/main/settings/SettingsScreens.kt

@@ -62,6 +62,7 @@ import androidx.compose.material.icons.filled.Notifications
 import androidx.compose.material.icons.filled.PhoneAndroid
 import androidx.compose.material.icons.filled.Palette
 import androidx.compose.material.icons.filled.Settings
+import androidx.compose.material.icons.filled.DeleteSweep
 import androidx.compose.material.icons.filled.Storage
 import androidx.compose.material.icons.filled.TabletAndroid
 import androidx.compose.material.icons.filled.VerifiedUser
@@ -126,7 +127,15 @@ import org.jetbrains.compose.resources.stringResource
 import ru.fromchat.Res
 import ru.fromchat.about
 import ru.fromchat.back
+import ru.fromchat.action_wipe_local_cache_confirm_body
+import ru.fromchat.action_wipe_local_cache_confirm_title
+import ru.fromchat.action_wipe_local_cache_done
+import ru.fromchat.action_wipe_local_cache_supporting
+import ru.fromchat.action_wipe_local_cache_title
 import ru.fromchat.api.ApiClient
+import ru.fromchat.api.db.MessageRepository
+import ru.fromchat.api.db.wipeLocalCacheOnDisk
+import ru.fromchat.core.cache.writeFromChatCacheGeneration
 import ru.fromchat.ui.imeScrollWithKeyboard
 import ru.fromchat.api.DeviceSessionInfo
 import ru.fromchat.ui.main.settings.SettingsSecurityPredictiveBackHandler
@@ -473,8 +482,14 @@ fun SettingsAppearanceScreen(onBack: () -> Unit) {
 @Composable
 fun SettingsServerToolsScreen(onBack: () -> Unit, outerNav: NavController) {
     val scrollBehavior = TopAppBarDefaults.exitUntilCollapsedScrollBehavior(rememberTopAppBarState())
+    val snackbarHostState = remember { SnackbarHostState() }
+    val scope = rememberCoroutineScope()
+    var showWipeLocalCacheConfirm by remember { mutableStateOf(false) }
+    var wipingLocalCache by remember { mutableStateOf(false) }
+    val wipeDoneMessage = stringResource(Res.string.action_wipe_local_cache_done)
 
     Scaffold(
+        snackbarHost = { FromChatSnackbarHost(snackbarHostState) },
         modifier = Modifier.nestedScroll(scrollBehavior.nestedScrollConnection),
         topBar = {
             MediumTopAppBar(
@@ -511,11 +526,57 @@ fun SettingsServerToolsScreen(onBack: () -> Unit, outerNav: NavController) {
                     headline = stringResource(Res.string.debug_tools),
                     supportingText = stringResource(Res.string.debug_tools_d),
                     onClick = { outerNav.navigate("debug") },
+                    divider = true,
+                    dividerColor = settingsSurfaceCutDividerColor(),
+                    dividerThickness = SettingsSurfaceCutDividerThickness,
                     leadingContent = { SettingsListLeadingIcon(Icons.Filled.BugReport) }
                 )
+                ListItem(
+                    headline = stringResource(Res.string.action_wipe_local_cache_title),
+                    supportingText = stringResource(Res.string.action_wipe_local_cache_supporting),
+                    onClick = { if (!wipingLocalCache) showWipeLocalCacheConfirm = true },
+                    enabled = !wipingLocalCache,
+                    divider = false,
+                    leadingContent = { SettingsListLeadingIcon(Icons.Filled.DeleteSweep) }
+                )
             }
         }
     }
+
+    if (showWipeLocalCacheConfirm) {
+        AlertDialog(
+            onDismissRequest = { if (!wipingLocalCache) showWipeLocalCacheConfirm = false },
+            title = { Text(stringResource(Res.string.action_wipe_local_cache_confirm_title)) },
+            text = { Text(stringResource(Res.string.action_wipe_local_cache_confirm_body)) },
+            confirmButton = {
+                TextButton(
+                    enabled = !wipingLocalCache,
+                    onClick = {
+                        wipingLocalCache = true
+                        scope.launch {
+                            runCatching {
+                                wipeLocalCacheOnDisk()
+                                writeFromChatCacheGeneration()
+                            }
+                            wipingLocalCache = false
+                            showWipeLocalCacheConfirm = false
+                            snackbarHostState.showSnackbar(wipeDoneMessage)
+                        }
+                    },
+                ) {
+                    Text(stringResource(Res.string.confirm))
+                }
+            },
+            dismissButton = {
+                TextButton(
+                    enabled = !wipingLocalCache,
+                    onClick = { showWipeLocalCacheConfirm = false },
+                ) {
+                    Text(stringResource(Res.string.cancel))
+                }
+            },
+        )
+    }
 }
 
 @OptIn(ExperimentalMaterial3Api::class, ExperimentalLayoutApi::class)

app/shared/src/commonMain/kotlin/ru/fromchat/ui/setup/ServerConfigScreen.kt

@@ -137,7 +137,14 @@ import ru.fromchat.server_config_snackbar_api_fail
 import ru.fromchat.server_config_snackbar_defaults
 import ru.fromchat.server_config_snackbar_ok_api_calls_bad
 import ru.fromchat.server_config_snackbar_ok_calls
+import ru.fromchat.server_config_snackbar_ok_calls_skip
+import ru.fromchat.server_config_snackbar_timeout
+import ru.fromchat.server_config_unsupported_no_instance_id
+import ru.fromchat.server_config_checking
 import ru.fromchat.server_config_subtitle
+import ru.fromchat.core.instance.ServerProbeResult
+import ru.fromchat.core.instance.applyServerAndNavigate
+import ru.fromchat.core.instance.probeServer
 import ru.fromchat.server_config_title
 import ru.fromchat.server_ip_hint
 import ru.fromchat.server_ip_label
@@ -435,6 +442,8 @@ fun ServerConfigScreen() {
     }
 
     var busy by remember { mutableStateOf(false) }
+    var lastProbe by remember { mutableStateOf<ServerProbeResult?>(null) }
+    var lastProbedConfig by remember { mutableStateOf<ServerConfigData?>(null) }
     var showResetDialog by remember { mutableStateOf(false) }
     val actionHazeState = rememberHazeState()
     val serverConfigListState = rememberLazyListState()
@@ -445,6 +454,9 @@ fun ServerConfigScreen() {
     val strPortError = stringResource(Res.string.server_config_port_error)
     val strSnackbarApiFail = stringResource(Res.string.server_config_snackbar_api_fail)
     val strSnackbarOkApiCallsBad = stringResource(Res.string.server_config_snackbar_ok_api_calls_bad)
+    val strSnackbarTimeout = stringResource(Res.string.server_config_snackbar_timeout)
+    val strUnsupportedInstance = stringResource(Res.string.server_config_unsupported_no_instance_id)
+    val strChecking = stringResource(Res.string.server_config_checking)
     val strResetConfirmTitle = stringResource(Res.string.server_config_action_reset_confirm_title)
     val strResetConfirmBody = stringResource(Res.string.server_config_action_reset_confirm_body)
 
@@ -473,50 +485,48 @@ fun ServerConfigScreen() {
         }
     }
 
+    fun buildTentativeConfig(): ServerConfigData? {
+        val host = serverIp.trim()
+        if (host.isEmpty() || !isValidIpOrHostname(host)) return null
+        if (apiPortText.isNotEmpty() && !isValidPortNumber(apiPortText)) return null
+        if (callsPortText.isNotEmpty() && !isValidPortNumber(callsPortText)) return null
+        return ServerConfigData(
+            serverIp = host,
+            apiPort = resolvedApiPort(apiPortText),
+            callsPort = effectiveCallsPort(callsPortText),
+            httpsEnabled = httpsEnabled,
+        )
+    }
+
     val verifyServer: () -> Unit = {
         scope.launch {
-            // Do not block actual checks on snackbar dismissal.
-            launch { snackbarHostState.showSnackbar("Checking...") }
-            val host = serverIp.trim()
-            if (host.isEmpty() || !isValidIpOrHostname(host)) {
-                snackbarHostState.showSnackbar(strHostError)
+            launch { snackbarHostState.showSnackbar(strChecking) }
+            val tentative = buildTentativeConfig()
+            if (tentative == null) {
+                snackbarHostState.showSnackbar(
+                    if (serverIp.isNotEmpty() && !isValidIpOrHostname(serverIp.trim())) {
+                        strHostError
+                    } else {
+                        strPortError
+                    },
+                )
                 return@launch
             }
-            if (apiPortText.isNotEmpty() && !isValidPortNumber(apiPortText)) {
-                snackbarHostState.showSnackbar(strPortError)
-                return@launch
-            }
-            if (callsPortText.isNotEmpty() && !isValidPortNumber(callsPortText)) {
-                snackbarHostState.showSnackbar(strPortError)
-                return@launch
-            }
-            val apiPort = resolvedApiPort(apiPortText)
-            val calls = effectiveCallsPort(callsPortText)
-            val tentative = ServerConfigData(
-                serverIp = host,
-                apiPort = apiPort,
-                callsPort = calls,
-                httpsEnabled = httpsEnabled,
-            )
-            val apiBase = apiBaseUrlFor(tentative)
-
-            val msg = runCatching {
-                withTimeout(3000) {
-                    val pingMark = TimeSource.Monotonic.markNow()
-                    val id = ApiClient.fetchServerInstanceId(apiBase)
-                    val pingMs = pingMark.elapsedNow().inWholeMilliseconds
-                        .toInt()
-                        .coerceAtLeast(0)
-                    if (id.isEmpty()) return@withTimeout strSnackbarApiFail
-
-                    val urlScheme = if (httpsEnabled) "https" else "http"
-                    val root = "$urlScheme://${hostForAuthority(host)}:${calls}/"
-                    val callsOk = ApiClient.probeHttpGet(root)
-                    if (callsOk) getString(Res.string.server_config_snackbar_ok_calls, pingMs)
-                    else strSnackbarOkApiCallsBad
+            val probe = probeServer(tentative)
+            lastProbe = probe
+            lastProbedConfig = tentative
+            val msg = when (probe) {
+                is ServerProbeResult.Supported -> {
+                    if (probe.callsOk) {
+                        getString(Res.string.server_config_snackbar_ok_calls, probe.pingMs)
+                    } else {
+                        getString(Res.string.server_config_snackbar_ok_calls_skip, probe.pingMs)
+                    }
                 }
-            }.getOrElse { strSnackbarApiFail }
-
+                ServerProbeResult.Unsupported -> strUnsupportedInstance
+                ServerProbeResult.Timeout -> strSnackbarTimeout
+                ServerProbeResult.Unreachable -> strSnackbarApiFail
+            }
             snackbarHostState.showSnackbar(msg)
         }
     }
@@ -605,61 +615,54 @@ fun ServerConfigScreen() {
                             scope.launch {
                                 busy = true
                                 try {
-                                    val tentative = ServerConfigData(
-                                        serverIp = serverIp.trim(),
-                                        apiPort = apiPortEffective,
-                                        callsPort = callsPortParsed,
-                                        httpsEnabled = httpsEnabled,
-                                    )
-                                    val tentativeApi = apiBaseUrlFor(tentative)
-                                    val newId = runCatching {
-                                        ApiClient.fetchServerInstanceId(tentativeApi)
-                                    }.getOrNull()?.trim().orEmpty()
-                                    if (newId.isEmpty()) {
-                                        withContext(Dispatchers.Main) {
-                                            reloginClearingSession(navController)
+                                    val tentative = buildTentativeConfig() ?: return@launch
+                                    val probe = if (
+                                        lastProbedConfig == tentative && lastProbe != null
+                                    ) {
+                                        lastProbe!!
+                                    } else {
+                                        probeServer(tentative).also {
+                                            lastProbe = it
+                                            lastProbedConfig = tentative
                                         }
-                                        return@launch
                                     }
-
-                                    val bearer = ApiClient.token?.trim().orEmpty()
-                                    if (bearer.isEmpty()) {
-                                        val callsOk = probeCallsReachable(tentative)
-                                        Config.updateServerConfig(tentative.copy(callsEnabled = callsOk))
-                                        Settings.lastKnownServerInstanceId = newId
-                                        WebSocketManager.disconnect()
-                                        withContext(Dispatchers.Main) {
-                                            navController.navigateAndWipeBackStack("login")
+                                    when (probe) {
+                                        ServerProbeResult.Unsupported -> {
+                                            snackbarHostState.showSnackbar(strUnsupportedInstance)
                                         }
-                                        return@launch
-                                    }
-
-                                    val persisted = Settings.lastKnownServerInstanceId.trim()
-                                    if (persisted.isNotEmpty() && !newId.equals(persisted, ignoreCase = true)) {
-                                        withContext(Dispatchers.Main) {
-                                            reloginClearingSession(navController)
+                                        ServerProbeResult.Timeout -> {
+                                            snackbarHostState.showSnackbar(strSnackbarTimeout)
                                         }
-                                        return@launch
-                                    }
-
-                                    val authOk = ApiClient.checkAuthAt(tentativeApi, bearer)
-                                    if (!authOk) {
-                                        withContext(Dispatchers.Main) {
-                                            reloginClearingSession(navController)
+                                        ServerProbeResult.Unreachable -> {
+                                            snackbarHostState.showSnackbar(strSnackbarApiFail)
                                         }
-                                        return@launch
-                                    }
-
-                                    val callsOk = probeCallsReachable(tentative)
-                                    Config.updateServerConfig(tentative.copy(callsEnabled = callsOk))
-                                    Settings.lastKnownServerInstanceId = newId
-                                    WebSocketManager.disconnect()
-                                    WebSocketManager.connect(forceRestart = true)
-                                    withContext(Dispatchers.Main) {
-                                        if (!navController.popBackStack()) {
-                                            navController.navigate("chat") {
-                                                popUpTo("login") { inclusive = true }
-                                            }
+                                        is ServerProbeResult.Supported -> {
+                                            Settings.lastKnownServerInstanceId = probe.instanceId
+                                            val bearer = ApiClient.token?.trim().orEmpty()
+                                            applyServerAndNavigate(
+                                                probe = probe,
+                                                config = tentative,
+                                                bearer = bearer,
+                                                onNavigateLogin = {
+                                                    withContext(Dispatchers.Main) {
+                                                        navController.navigateAndWipeBackStack("login")
+                                                    }
+                                                },
+                                                onNavigateChat = {
+                                                    withContext(Dispatchers.Main) {
+                                                        if (!navController.popBackStack()) {
+                                                            navController.navigate("chat") {
+                                                                popUpTo("login") { inclusive = true }
+                                                            }
+                                                        }
+                                                    }
+                                                },
+                                                onLogoutOldHost = {
+                                                    withContext(Dispatchers.Main) {
+                                                        reloginClearingSession(navController)
+                                                    }
+                                                },
+                                            )
                                         }
                                     }
                                 } finally {

app/shared/src/commonMain/sqldelight/ru/fromchat/db/MessageDatabase.sq

@@ -1,15 +1,30 @@
+CREATE TABLE server_binding (
+    configKey TEXT NOT NULL PRIMARY KEY,
+    activeInstanceId TEXT NOT NULL,
+    updatedAt TEXT
+);
+
+CREATE TABLE instance_registry (
+    instanceId TEXT NOT NULL PRIMARY KEY,
+    firstSeenAt TEXT NOT NULL,
+    lastSeenAt TEXT NOT NULL
+);
+
 CREATE TABLE conversation (
-    id TEXT NOT NULL PRIMARY KEY,
-    type TEXT NOT NULL, -- "public" or "dm"
+    instanceId TEXT NOT NULL,
+    id TEXT NOT NULL,
+    type TEXT NOT NULL,
     otherUserId INTEGER,
     displayName TEXT,
     lastMessageId INTEGER,
     lastMessagePreview TEXT,
     unreadCount INTEGER NOT NULL DEFAULT 0,
-    updatedAt TEXT
+    updatedAt TEXT,
+    PRIMARY KEY (instanceId, id)
 );
 
 CREATE TABLE message (
+    instanceId TEXT NOT NULL,
     id INTEGER NOT NULL,
     conversationId TEXT NOT NULL,
     userId INTEGER NOT NULL,
@@ -20,55 +35,120 @@ CREATE TABLE message (
     replyToId INTEGER,
     clientMessageId TEXT,
     deletedFlag INTEGER NOT NULL DEFAULT 0,
-    PRIMARY KEY (id, conversationId)
+    sendStatus TEXT,
+    PRIMARY KEY (instanceId, conversationId, id)
 );
 
-CREATE INDEX message_conversation_index ON message(conversationId, timestamp);
+CREATE INDEX message_instance_conversation_index ON message(instanceId, conversationId, timestamp);
 
 CREATE TABLE attachment (
+    instanceId TEXT NOT NULL,
     id INTEGER NOT NULL,
     messageId INTEGER NOT NULL,
     conversationId TEXT NOT NULL,
     remotePath TEXT,
     localPath TEXT,
-    status TEXT NOT NULL, -- "PENDING", "DOWNLOADING", "READY"
+    status TEXT NOT NULL,
     blurhash TEXT,
     aspectRatio REAL,
     size INTEGER,
-    PRIMARY KEY (id, messageId, conversationId)
+    bytesTransferred INTEGER NOT NULL DEFAULT 0,
+    clientMessageId TEXT,
+    PRIMARY KEY (instanceId, id, messageId, conversationId)
 );
 
+CREATE TABLE outbox (
+    instanceId TEXT NOT NULL,
+    clientMessageId TEXT NOT NULL,
+    conversationId TEXT NOT NULL,
+    kind TEXT NOT NULL,
+    payloadJson TEXT NOT NULL,
+    retryCount INTEGER NOT NULL DEFAULT 0,
+    nextAttemptAt TEXT,
+    bytesUploaded INTEGER NOT NULL DEFAULT 0,
+    PRIMARY KEY (instanceId, clientMessageId)
+);
+
+CREATE TABLE profile_cache (
+    instanceId TEXT NOT NULL,
+    userId INTEGER NOT NULL,
+    json TEXT NOT NULL,
+    PRIMARY KEY (instanceId, userId)
+);
+
+-- server_binding
+selectActiveInstanceIdForConfig:
+SELECT activeInstanceId FROM server_binding WHERE configKey = ?;
+
+upsertServerBinding:
+INSERT OR REPLACE INTO server_binding(configKey, activeInstanceId, updatedAt)
+VALUES (?, ?, ?);
+
+deleteServerBinding:
+DELETE FROM server_binding WHERE configKey = ?;
+
+-- instance_registry
+upsertInstanceRegistry:
+INSERT OR REPLACE INTO instance_registry(instanceId, firstSeenAt, lastSeenAt)
+VALUES (?, ?, ?);
+
+touchInstanceRegistry:
+UPDATE instance_registry SET lastSeenAt = ? WHERE instanceId = ?;
+
+selectAllInstanceIds:
+SELECT instanceId FROM instance_registry;
+
+-- messages
 selectMessagesByConversation:
 SELECT *
 FROM message
-WHERE conversationId = ? AND deletedFlag = 0
+WHERE instanceId = ? AND conversationId = ? AND deletedFlag = 0
 ORDER BY timestamp ASC;
 
--- Last N rows for a conversation (newest first in SQL; reverse in Kotlin for chronological UI).
 selectRecentMessagesByConversation:
 SELECT *
 FROM message
-WHERE conversationId = ? AND deletedFlag = 0
+WHERE instanceId = ? AND conversationId = ? AND deletedFlag = 0
 ORDER BY timestamp DESC
 LIMIT :limit;
 
--- Optimistic rows only (avoid scanning the full conversation on replace).
 selectPendingMessagesByConversation:
 SELECT *
 FROM message
-WHERE conversationId = ? AND deletedFlag = 0 AND id < 0
+WHERE instanceId = ? AND conversationId = ? AND deletedFlag = 0 AND id < 0
 ORDER BY timestamp ASC;
 
+selectSentMessageIdByClientMessageId:
+SELECT id
+FROM message
+WHERE instanceId = ? AND conversationId = ? AND clientMessageId = ? AND id > 0 AND deletedFlag = 0
+LIMIT 1;
+
+selectMessageById:
+SELECT *
+FROM message
+WHERE instanceId = ? AND conversationId = ? AND id = ? AND deletedFlag = 0
+LIMIT 1;
+
 deleteMessagesForConversation:
 DELETE FROM message
-WHERE conversationId = ?;
+WHERE instanceId = ? AND conversationId = ?;
 
 deleteMessageByClientMessageId:
 DELETE FROM message
-WHERE conversationId = ? AND clientMessageId = ?;
+WHERE instanceId = ? AND conversationId = ? AND clientMessageId = ?;
+
+deletePendingMessageByClientMessageId:
+DELETE FROM message
+WHERE instanceId = ? AND conversationId = ? AND clientMessageId = ? AND id < 0;
+
+deleteMessageById:
+DELETE FROM message
+WHERE instanceId = ? AND conversationId = ? AND id = ?;
 
 upsertMessage:
 INSERT OR REPLACE INTO message(
+    instanceId,
     id,
     conversationId,
     userId,
@@ -78,21 +158,49 @@ INSERT OR REPLACE INTO message(
     isEdited,
     replyToId,
     clientMessageId,
-    deletedFlag
-) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?);
+    deletedFlag,
+    sendStatus
+) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?);
 
 markMessageDeleted:
 UPDATE message
 SET deletedFlag = 1
-WHERE id = ? AND conversationId = ?;
+WHERE instanceId = ? AND id = ? AND conversationId = ?;
 
-selectConversations:
+deleteAllMessagesForInstance:
+DELETE FROM message WHERE instanceId = ?;
+
+deleteAllConversationsForInstance:
+DELETE FROM conversation WHERE instanceId = ?;
+
+deleteAllOutboxForInstance:
+DELETE FROM outbox WHERE instanceId = ?;
+
+deleteAllAttachmentsForInstance:
+DELETE FROM attachment WHERE instanceId = ?;
+
+deleteAllProfilesForInstance:
+DELETE FROM profile_cache WHERE instanceId = ?;
+
+purgeAllCache:
+DELETE FROM message;
+DELETE FROM conversation;
+DELETE FROM outbox;
+DELETE FROM attachment;
+DELETE FROM profile_cache;
+DELETE FROM server_binding;
+DELETE FROM instance_registry;
+
+-- conversations
+selectConversationsForInstance:
 SELECT *
 FROM conversation
+WHERE instanceId = ?
 ORDER BY updatedAt DESC;
 
 upsertConversation:
 INSERT OR REPLACE INTO conversation(
+    instanceId,
     id,
     type,
     otherUserId,
@@ -101,5 +209,43 @@ INSERT OR REPLACE INTO conversation(
     lastMessagePreview,
     unreadCount,
     updatedAt
+) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?);
+
+-- outbox
+selectPendingOutboxForInstance:
+SELECT * FROM outbox WHERE instanceId = ? ORDER BY clientMessageId ASC;
+
+upsertOutbox:
+INSERT OR REPLACE INTO outbox(
+    instanceId,
+    clientMessageId,
+    conversationId,
+    kind,
+    payloadJson,
+    retryCount,
+    nextAttemptAt,
+    bytesUploaded
 ) VALUES (?, ?, ?, ?, ?, ?, ?, ?);
 
+deleteOutboxItem:
+DELETE FROM outbox WHERE instanceId = ? AND clientMessageId = ?;
+
+selectOutboxItem:
+SELECT * FROM outbox WHERE instanceId = ? AND clientMessageId = ? LIMIT 1;
+
+-- profile
+upsertProfileCache:
+INSERT OR REPLACE INTO profile_cache(instanceId, userId, json)
+VALUES (?, ?, ?);
+
+selectProfileCache:
+SELECT json FROM profile_cache WHERE instanceId = ? AND userId = ?;
+
+selectAllProfilesForInstance:
+SELECT userId, json FROM profile_cache WHERE instanceId = ?;
+
+deleteProfileCache:
+DELETE FROM profile_cache WHERE instanceId = ? AND userId = ?;
+
+deleteAllProfileCache:
+DELETE FROM profile_cache;

app/shared/src/iosMain/kotlin/ru/fromchat/api/ApiClient.ios.kt

@@ -22,8 +22,9 @@ actual fun createPlatformHttpClient(
         }
 
         install(HttpTimeout) {
-            requestTimeoutMillis = 30000
-            connectTimeoutMillis = 30000
+            requestTimeoutMillis = 30_000
+            connectTimeoutMillis = 5_000
+            socketTimeoutMillis = 30_000
         }
 
         block(this)

app/shared/src/iosMain/kotlin/ru/fromchat/api/AttachmentUploadQueue.ios.kt

@@ -1,45 +1,17 @@
 package ru.fromchat.api
 
-import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.SupervisorJob
-import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.SharedFlow
-import kotlinx.coroutines.launch
-
-private val iosUploadScope = CoroutineScope(SupervisorJob() + Dispatchers.Default)
+import ru.fromchat.api.outbox.scheduleOutboxProcessing
+import ru.fromchat.core.cache.CacheContext
 
 actual object AttachmentUploadQueue {
-    private val _progressFlow = MutableSharedFlow<AttachmentUploadProgress>(extraBufferCapacity = 64)
-    actual val progressFlow: SharedFlow<AttachmentUploadProgress> = _progressFlow
+    actual val progressFlow: SharedFlow<AttachmentUploadProgress> = AttachmentUploadNotifier.progressFlow
 
     actual fun enqueue(job: AttachmentUploadJob) {
-        _progressFlow.tryEmit(AttachmentUploadProgress.Pending(job.jobId, job.filename))
-        iosUploadScope.launch {
-            // Phase 1 placeholder on iOS: eager message-only send to keep API functional.
-            // Full background resumable URLSession integration is completed in Phase 4.
-            runCatching {
-                ApiClient.sendDm(
-                    recipientId = job.recipientId,
-                    plaintext = job.plaintext,
-                    clientMessageId = job.jobId,
-                    replyToId = job.replyToId
-                )
-            }.onSuccess {
-                _progressFlow.tryEmit(AttachmentUploadProgress.Success(job.jobId))
-            }.onFailure { error ->
-                _progressFlow.tryEmit(
-                    AttachmentUploadProgress.Failed(
-                        jobId = job.jobId,
-                        error = error.message ?: "Upload failed"
-                    )
-                )
-            }
-        }
+        scheduleOutboxProcessing(CacheContext.activeInstanceId.value.trim())
     }
 
     actual fun cancel(jobId: String) {
-        // No-op in the Phase 1 iOS eager placeholder implementation.
+        // Outbox + artifact cleanup handled when user deletes pending message from UI.
     }
 }
-

app/shared/src/iosMain/kotlin/ru/fromchat/api/db/MessageDatabaseDriver.ios.kt

@@ -2,12 +2,26 @@ package ru.fromchat.api.db
 
 import app.cash.sqldelight.db.SqlDriver
 import app.cash.sqldelight.driver.native.NativeSqliteDriver
+import kotlinx.cinterop.ExperimentalForeignApi
+import platform.Foundation.NSCachesDirectory
+import platform.Foundation.NSFileManager
+import platform.Foundation.NSUserDomainMask
 import ru.fromchat.db.MessageDatabase
 
+@OptIn(ExperimentalForeignApi::class)
 actual fun provideMessageDatabaseDriver(): SqlDriver {
+    val base = NSFileManager.defaultManager.URLForDirectory(
+        directory = NSCachesDirectory,
+        inDomain = NSUserDomainMask,
+        appropriateForURL = null,
+        create = true,
+        error = null,
+    )?.path ?: "."
+    val dir = "$base/fromchat"
+    NSFileManager.defaultManager.createDirectoryAtPath(dir, true, null, null)
     return NativeSqliteDriver(
         schema = MessageDatabase.Schema,
-        name = "message_database.db"
+        name = "$dir/message_database.db",
     )
 }
 

app/shared/src/iosMain/kotlin/ru/fromchat/api/db/MessageDatabaseLock.ios.kt

@@ -0,0 +1,14 @@
+package ru.fromchat.api.db
+
+import platform.Foundation.NSRecursiveLock
+
+private val lock = NSRecursiveLock()
+
+internal actual fun <T> withMessageDatabaseLock(block: () -> T): T {
+    lock.lock()
+    try {
+        return block()
+    } finally {
+        lock.unlock()
+    }
+}

app/shared/src/iosMain/kotlin/ru/fromchat/api/outbox/OutboxProcessor.ios.kt

@@ -0,0 +1,14 @@
+package ru.fromchat.api.outbox
+
+import kotlinx.coroutines.MainScope
+import kotlinx.coroutines.launch
+
+/** iOS: drain outbox on enqueue and when the app returns to foreground (parity with WorkManager). */
+actual fun scheduleOutboxProcessing(instanceId: String) {
+    if (instanceId.trim().isEmpty()) return
+    MainScope().launch {
+        OutgoingMessageCoordinator.drainActiveInstanceOutbox()
+    }
+}
+
+actual fun cancelOutboxProcessing(instanceId: String) = Unit

app/shared/src/iosMain/kotlin/ru/fromchat/core/cache/FromChatCacheDirs.ios.kt

@@ -0,0 +1,23 @@
+package ru.fromchat.core.cache
+
+import kotlinx.cinterop.ExperimentalForeignApi
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import platform.Foundation.NSCachesDirectory
+import platform.Foundation.NSFileManager
+import platform.Foundation.NSUserDomainMask
+
+@OptIn(ExperimentalForeignApi::class)
+actual suspend fun wipeFromChatCacheDirectory() {
+    withContext(Dispatchers.Default) {
+        val url = NSFileManager.defaultManager.URLForDirectory(
+            directory = NSCachesDirectory,
+            inDomain = NSUserDomainMask,
+            appropriateForURL = null,
+            create = false,
+            error = null,
+        ) ?: return@withContext
+        val path = url.path + "/fromchat"
+        NSFileManager.defaultManager.removeItemAtPath(path, error = null)
+    }
+}

app/shared/src/iosMain/kotlin/ru/fromchat/core/cache/FromChatCacheGeneration.ios.kt

@@ -0,0 +1,61 @@
+package ru.fromchat.core.cache
+
+import kotlinx.cinterop.ExperimentalForeignApi
+import kotlinx.cinterop.addressOf
+import kotlinx.cinterop.usePinned
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import platform.Foundation.NSCachesDirectory
+import platform.Foundation.NSData
+import platform.Foundation.NSFileManager
+import platform.Foundation.NSUserDomainMask
+import platform.Foundation.create
+import platform.Foundation.writeToFile
+import ru.fromchat.api.db.MessageDatabaseProvider
+
+private const val GENERATION_FILE = ".generation"
+
+@OptIn(ExperimentalForeignApi::class)
+private fun fromChatRoot(): String {
+    val url = NSFileManager.defaultManager.URLForDirectory(
+        directory = NSCachesDirectory,
+        inDomain = NSUserDomainMask,
+        appropriateForURL = null,
+        create = true,
+        error = null,
+    ) ?: return ""
+    return url.path + "/fromchat"
+}
+
+@OptIn(ExperimentalForeignApi::class)
+private fun writeGenerationMarker(path: String) {
+    val bytes = "1\n".encodeToByteArray()
+    bytes.usePinned { pinned ->
+        val data = NSData.create(bytes = pinned.addressOf(0), length = bytes.size.toULong())
+        data?.writeToFile(path, true)
+    }
+}
+
+@OptIn(ExperimentalForeignApi::class)
+actual suspend fun ensureFromChatCacheGeneration() {
+    withContext(Dispatchers.Default) {
+        val root = fromChatRoot()
+        if (root.isEmpty()) return@withContext
+        val marker = "$root/$GENERATION_FILE"
+        if (NSFileManager.defaultManager.fileExistsAtPath(marker)) return@withContext
+        MessageDatabaseProvider.closeAndReset()
+        wipeFromChatCacheDirectory()
+        NSFileManager.defaultManager.createDirectoryAtPath(root, true, null, null)
+        writeGenerationMarker(marker)
+    }
+}
+
+@OptIn(ExperimentalForeignApi::class)
+actual suspend fun writeFromChatCacheGeneration() {
+    withContext(Dispatchers.Default) {
+        val root = fromChatRoot()
+        if (root.isEmpty()) return@withContext
+        NSFileManager.defaultManager.createDirectoryAtPath(root, true, null, null)
+        writeGenerationMarker("$root/$GENERATION_FILE")
+    }
+}

app/shared/src/iosMain/kotlin/ru/fromchat/core/cache/ResumableUploadStorage.ios.kt

@@ -0,0 +1,146 @@
+package ru.fromchat.core.cache
+
+import kotlinx.cinterop.BetaInteropApi
+import kotlinx.cinterop.ByteVar
+import kotlinx.cinterop.ExperimentalForeignApi
+import kotlinx.cinterop.addressOf
+import kotlinx.cinterop.get
+import kotlinx.cinterop.reinterpret
+import kotlinx.cinterop.usePinned
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import platform.Foundation.NSCachesDirectory
+import platform.Foundation.NSData
+import platform.Foundation.NSFileManager
+import platform.Foundation.NSURL
+import platform.Foundation.NSUserDomainMask
+import platform.Foundation.create
+import platform.Foundation.dataWithContentsOfURL
+import platform.Foundation.writeToFile
+
+@OptIn(ExperimentalForeignApi::class)
+private fun uploadDir(instanceId: String): String {
+    val url = NSFileManager.defaultManager.URLForDirectory(
+        directory = NSCachesDirectory,
+        inDomain = NSUserDomainMask,
+        appropriateForURL = null,
+        create = true,
+        error = null,
+    ) ?: return ""
+    val safe = instanceId.replace(Regex("[^a-zA-Z0-9._-]"), "_")
+    val path = url.path + "/fromchat/instances/$safe/uploads"
+    NSFileManager.defaultManager.createDirectoryAtPath(path, true, null, null)
+    return path
+}
+
+@OptIn(ExperimentalForeignApi::class)
+private fun blobPath(instanceId: String, clientMessageId: String): String {
+    val safeId = clientMessageId.replace(Regex("[^a-zA-Z0-9._-]"), "_")
+    return "${uploadDir(instanceId)}/$safeId.enc"
+}
+
+@OptIn(ExperimentalForeignApi::class)
+private fun cipherPath(instanceId: String, clientMessageId: String): String {
+    val safeId = clientMessageId.replace(Regex("[^a-zA-Z0-9._-]"), "_")
+    return "${uploadDir(instanceId)}/$safeId.cipher.json"
+}
+
+private fun sourcePath(instanceId: String, clientMessageId: String): String {
+    val safeId = clientMessageId.replace(Regex("[^a-zA-Z0-9._-]"), "_")
+    return "${uploadDir(instanceId)}/$safeId.source"
+}
+
+@OptIn(ExperimentalForeignApi::class, BetaInteropApi::class)
+private fun readBytesAtPath(path: String): ByteArray? {
+    if (!NSFileManager.defaultManager.fileExistsAtPath(path)) return null
+    val data = NSData.create(contentsOfFile = path) ?: return null
+    val length = data.length.toInt()
+    if (length == 0) return null
+    val bytesPtr = data.bytes ?: return null
+    val bytePtr = bytesPtr.reinterpret<ByteVar>()
+    return ByteArray(length) { i -> bytePtr[i] }
+}
+
+@OptIn(ExperimentalForeignApi::class, BetaInteropApi::class)
+private fun writeBytesAtPath(path: String, bytes: ByteArray) {
+    bytes.usePinned { pinned ->
+        val data = NSData.create(bytes = pinned.addressOf(0), length = bytes.size.toULong())
+        data?.writeToFile(path, true)
+    }
+}
+
+@OptIn(ExperimentalForeignApi::class)
+actual suspend fun stageOutboundFileForUpload(
+    instanceId: String,
+    clientMessageId: String,
+    sourceUri: String,
+): StagedOutboundFile = withContext(Dispatchers.Default) {
+    val dest = sourcePath(instanceId, clientMessageId)
+    if (sourceUri != dest) {
+        val existing = readBytesAtPath(dest)
+        if (existing == null || existing.isEmpty()) {
+            val bytes = readOutboundFileBytes(sourceUri)
+            if (bytes.isEmpty()) {
+                throw OutboundFileUnavailableException("File is empty or unavailable")
+            }
+            writeBytesAtPath(dest, bytes)
+        }
+    }
+    val size = readBytesAtPath(dest)?.size?.toLong() ?: 0L
+    StagedOutboundFile(uri = dest, sizeBytes = size)
+}
+
+@OptIn(ExperimentalForeignApi::class)
+actual suspend fun readOutboundFileBytes(fileUri: String): ByteArray =
+    withContext(Dispatchers.Default) {
+        val url = NSURL.URLWithString(fileUri) ?: throw OutboundFileUnavailableException("Invalid file URI")
+        val data = NSData.dataWithContentsOfURL(url)
+            ?: throw OutboundFileUnavailableException("Failed to read file from URI")
+        val length = data.length.toInt()
+        val bytesPtr = data.bytes ?: error("Empty file")
+        val bytePtr = bytesPtr.reinterpret<ByteVar>()
+        ByteArray(length) { i -> bytePtr[i] }
+    }
+
+@OptIn(ExperimentalForeignApi::class)
+actual suspend fun saveEncryptedUploadBlob(instanceId: String, clientMessageId: String, bytes: ByteArray) {
+    withContext(Dispatchers.Default) {
+        writeBytesAtPath(blobPath(instanceId, clientMessageId), bytes)
+    }
+}
+
+@OptIn(ExperimentalForeignApi::class)
+actual suspend fun loadEncryptedUploadBlob(instanceId: String, clientMessageId: String): ByteArray? =
+    withContext(Dispatchers.Default) {
+        readBytesAtPath(blobPath(instanceId, clientMessageId))
+    }
+
+@OptIn(ExperimentalForeignApi::class)
+actual suspend fun saveUploadTransportCipherJson(instanceId: String, clientMessageId: String, json: String) {
+    withContext(Dispatchers.Default) {
+        writeBytesAtPath(cipherPath(instanceId, clientMessageId), json.encodeToByteArray())
+    }
+}
+
+@OptIn(ExperimentalForeignApi::class)
+actual suspend fun loadUploadTransportCipherJson(instanceId: String, clientMessageId: String): String? =
+    withContext(Dispatchers.Default) {
+        readBytesAtPath(cipherPath(instanceId, clientMessageId))?.decodeToString()?.takeIf { it.isNotBlank() }
+    }
+
+@OptIn(ExperimentalForeignApi::class)
+actual suspend fun clearUploadArtifacts(instanceId: String, clientMessageId: String) {
+    withContext(Dispatchers.Default) {
+        NSFileManager.defaultManager.removeItemAtPath(blobPath(instanceId, clientMessageId), null)
+        NSFileManager.defaultManager.removeItemAtPath(cipherPath(instanceId, clientMessageId), null)
+        NSFileManager.defaultManager.removeItemAtPath(sourcePath(instanceId, clientMessageId), null)
+    }
+}
+
+@OptIn(ExperimentalForeignApi::class)
+actual suspend fun clearUploadSecretsOnly(instanceId: String, clientMessageId: String) {
+    withContext(Dispatchers.Default) {
+        NSFileManager.defaultManager.removeItemAtPath(blobPath(instanceId, clientMessageId), null)
+        NSFileManager.defaultManager.removeItemAtPath(cipherPath(instanceId, clientMessageId), null)
+    }
+}

app/shared/src/iosMain/kotlin/ru/fromchat/crypto/dm/DmCrypto.ios.kt

@@ -40,7 +40,7 @@ actual object DmCrypto {
     actual suspend fun decryptEnvelope(
         ivB64: String,
         ciphertextB64: String,
-        mek: ByteArray
+        mek: ByteArray,
     ) = withContext(Dispatchers.Default) {
         val key = mek.require("MEK must be 32 bytes") {
             it.size == AES_KEY_SIZE
@@ -62,6 +62,29 @@ actual object DmCrypto {
         }
     }
 
+    actual suspend fun decryptAesGcm(
+        ivB64: String,
+        ciphertext: ByteArray,
+        mek: ByteArray,
+    ) = withContext(Dispatchers.Default) {
+        val key = mek.require("MEK must be 32 bytes") {
+            it.size == AES_KEY_SIZE
+        }
+        val iv = Base64
+            .decode(ivB64)
+            .require("IV must be 12 bytes") {
+                it.size == GCM_IV_SIZE
+            }
+        ciphertext.require("Ciphertext too short") {
+            it.size >= GCM_TAG_SIZE
+        }
+        try {
+            aesGcmDecrypt(key, iv, ciphertext)
+        } catch (e: Throwable) {
+            throw DmCiphertextCorruptedException(cause = e)
+        }
+    }
+
     private suspend fun aesGcmDecrypt(key: ByteArray, iv: ByteArray, ciphertext: ByteArray): ByteArray {
         require(iv.size == GCM_IV_SIZE) { "IV must be 12 bytes for GCM" }
         require(key.size == AES_KEY_SIZE) { "Key must be 32 bytes" }

app/shared/src/iosMain/kotlin/ru/fromchat/ui/chat/AttachmentPickers.ios.kt

@@ -17,3 +17,5 @@ actual fun rememberFilePicker(onResult: (List<String>) -> Unit): () -> Unit {
 }
 
 actual suspend fun getImageAspectRatio(uri: String): Float? = null
+
+actual suspend fun getImageDimensions(uri: String): Pair<Int, Int>? = null

app/shared/src/iosMain/kotlin/ru/fromchat/ui/chat/LocalDecodedImageCache.ios.kt

@@ -0,0 +1,94 @@
+@file:OptIn(kotlinx.cinterop.ExperimentalForeignApi::class, kotlinx.cinterop.BetaInteropApi::class)
+
+package ru.fromchat.ui.chat
+
+import androidx.compose.ui.graphics.ImageBitmap
+import androidx.compose.ui.graphics.toComposeImageBitmap
+import kotlinx.cinterop.ByteVar
+import kotlinx.cinterop.ExperimentalForeignApi
+import kotlinx.cinterop.get
+import kotlinx.cinterop.reinterpret
+import kotlinx.cinterop.useContents
+import org.jetbrains.skia.Bitmap
+import org.jetbrains.skia.Image
+import org.jetbrains.skia.ImageInfo
+import org.jetbrains.skia.SamplingMode
+import platform.CoreGraphics.CGRectMake
+import platform.Foundation.NSData
+import platform.Foundation.create
+import platform.UIKit.UIGraphicsBeginImageContextWithOptions
+import platform.UIKit.UIGraphicsEndImageContext
+import platform.UIKit.UIGraphicsGetImageFromCurrentImageContext
+import platform.UIKit.UIImage
+import platform.UIKit.UIImageOrientation
+import platform.UIKit.UIImagePNGRepresentation
+
+actual object PlatformDecodedBitmapCache {
+    private val cache = mutableMapOf<String, ImageBitmap>()
+
+    actual fun get(key: String): ImageBitmap? = cache[key]
+
+    actual fun put(key: String, bitmap: ImageBitmap) {
+        cache[key] = bitmap
+    }
+
+    actual fun remove(key: String) {
+        cache.remove(key)
+    }
+
+    actual fun evictPrefix(prefix: String) {
+        val keys = cache.keys.filter { it.startsWith(prefix) }
+        for (key in keys) {
+            cache.remove(key)
+        }
+    }
+}
+
+actual fun decodeLocalImageFile(absolutePath: String, reqWidthPx: Int, reqHeightPx: Int): ImageBitmap? {
+    val data = NSData.create(contentsOfFile = absolutePath) ?: return null
+    val uiImage = UIImage.imageWithData(data) ?: return null
+    val normalized = normalizeUiImageOrientation(uiImage)
+    val pngData = UIImagePNGRepresentation(normalized) ?: return null
+    return decodeImageBytes(nsDataToByteArray(pngData), reqWidthPx, reqHeightPx)
+}
+
+actual fun decodeImageBytes(bytes: ByteArray, reqWidthPx: Int, reqHeightPx: Int): ImageBitmap? =
+    runCatching {
+        val image = Image.makeFromEncoded(bytes) ?: return@runCatching null
+        scaleSkiaImageToFitWithin(image, reqWidthPx, reqHeightPx)
+    }.getOrNull()
+
+private fun normalizeUiImageOrientation(image: UIImage): UIImage {
+    if (image.imageOrientation == UIImageOrientation.UIImageOrientationUp) return image
+    val width = image.size.useContents { width }
+    val height = image.size.useContents { height }
+    UIGraphicsBeginImageContextWithOptions(image.size, false, image.scale)
+    image.drawInRect(CGRectMake(0.0, 0.0, width, height))
+    val normalized = UIGraphicsGetImageFromCurrentImageContext()
+    UIGraphicsEndImageContext()
+    return normalized ?: image
+}
+
+private fun nsDataToByteArray(data: NSData): ByteArray {
+    val length = data.length.toInt()
+    if (length <= 0) return ByteArray(0)
+    val bytesPtr = data.bytes ?: return ByteArray(0)
+    val bytePtr = bytesPtr.reinterpret<ByteVar>()
+    return ByteArray(length) { i -> bytePtr[i] }
+}
+
+private fun scaleSkiaImageToFitWithin(image: Image, reqWidthPx: Int, reqHeightPx: Int): ImageBitmap {
+    if (image.width <= reqWidthPx && image.height <= reqHeightPx) return image.toComposeImageBitmap()
+    val scale = minOf(
+        reqWidthPx.toFloat() / image.width.toFloat(),
+        reqHeightPx.toFloat() / image.height.toFloat(),
+    )
+    if (scale >= 1f) return image.toComposeImageBitmap()
+    val dstW = (image.width * scale).toInt().coerceAtLeast(1)
+    val dstH = (image.height * scale).toInt().coerceAtLeast(1)
+    val dst = Bitmap()
+    dst.allocPixels(ImageInfo.makeN32Premul(dstW, dstH))
+    val pixmap = dst.peekPixels() ?: return image.toComposeImageBitmap()
+    image.scalePixels(pixmap, SamplingMode.LINEAR, true)
+    return Image.makeFromBitmap(dst).toComposeImageBitmap()
+}

gradle/libs.versions.toml

@@ -3,6 +3,7 @@ agp = "9.1.1"
 androidx-activityCompose = "1.13.0"
 androidx-appcompat = "1.7.1"
 androidx-core-ktx = "1.18.0"
+androidx-exifinterface = "1.3.7"
 coilCompose = "3.4.0"
 compose-multiplatform = "1.10.3"
 #noinspection NewerVersionAvailable
@@ -47,6 +48,7 @@ livekitAndroidComposeComponents = "2.3.0"
 [libraries]
 androidx-core-splashscreen = { module = "androidx.core:core-splashscreen", version.ref = "coreSplashscreen" }
 androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "androidx-core-ktx" }
+androidx-exifinterface = { module = "androidx.exifinterface:exifinterface", version.ref = "androidx-exifinterface" }
 androidx-appcompat = { group = "androidx.appcompat", name = "appcompat", version.ref = "androidx-appcompat" }
 androidx-activity-compose = { module = "androidx.activity:activity-compose", version.ref = "androidx-activityCompose" }
 androidx-lifecycle-runtime-compose = { module = "androidx.lifecycle:lifecycle-runtime-compose", version.ref = "lifecycleRuntimeKtx" }

utils/shared/src/androidMain/kotlin/com/pr0gramm3r101/utils/ClipboardSupport.android.kt

@@ -0,0 +1,27 @@
+package com.pr0gramm3r101.utils
+
+import android.content.ClipData as AndroidClipData
+import androidx.compose.ui.platform.ClipEntry
+import androidx.compose.ui.platform.Clipboard
+
+actual fun Clipboard.toSupport(): SupportClipboardManager {
+    val clipboard = this
+    return object : SupportClipboardManager {
+        private var listener: ((String) -> Unit)? = null
+
+        override suspend fun setText(string: String) {
+            val clipData = AndroidClipData.newPlainText("text", string)
+            clipboard.setClipEntry(ClipEntry(clipData))
+            listener?.invoke(string)
+        }
+
+        override suspend fun getText(): String? {
+            val entry = clipboard.getClipEntry() ?: return null
+            return entry.clipData?.getItemAt(0)?.text?.toString()
+        }
+
+        override fun setTextListener(listener: (String) -> Unit) {
+            this.listener = listener
+        }
+    }
+}

utils/shared/src/androidMain/kotlin/com/pr0gramm3r101/utils/files/PlatformFileSystem.android.kt

@@ -7,7 +7,9 @@ internal actual fun expectExists(path: String): Boolean =
     File(path).exists()
 
 internal actual fun expectWriteBytes(path: String, bytes: ByteArray) {
-    File(path).writeBytes(bytes)
+    val file = File(path)
+    file.parentFile?.mkdirs()
+    file.writeBytes(bytes)
 }
 
 internal actual fun expectDelete(path: String) {