Implement live last message update

frontend/src/pages/chat/ui/right/ChatMessages.tsx

@@ -154,7 +154,10 @@ export function ChatMessages({ messages = [], children, isDm = false, onReplySel
                     <Message
                         key={message.id}
                         message={message}
-                        isAuthor={message.username === user.currentUser?.username}
+                        isAuthor={isDm ? 
+                            (message.runtimeData?.dmEnvelope?.senderId === user.currentUser?.id) : 
+                            (message.username === user.currentUser?.username)
+                        }
                         onProfileClick={handleProfileClick}
                         onContextMenu={handleContextMenu}
                         onReactionClick={handleReactionClick}
@@ -189,7 +192,10 @@ export function ChatMessages({ messages = [], children, isDm = false, onReplySel
             {contextMenu.message && (
                 <MessageContextMenu
                     message={contextMenu.message}
-                    isAuthor={contextMenu.message.username === user.currentUser?.username}
+                    isAuthor={isDm ? 
+                        (contextMenu.message.runtimeData?.dmEnvelope?.senderId === user.currentUser?.id) : 
+                        (contextMenu.message.username === user.currentUser?.username)
+                    }
                     onEdit={handleEdit}
                     onReply={handleReply}
                     onDelete={handleDelete}

frontend/src/pages/chat/ui/right/panels/DMPanel.ts

@@ -9,6 +9,7 @@ import {
 } from "@/core/api/dmApi";
 import type { DmEncryptedJSON, DmEnvelope, DMWebSocketMessage, EncryptedMessageJson, Message } from "@/core/types";
 import type { UserState } from "@/pages/chat/state";
+import { formatDMUsername } from "@/pages/chat/hooks/useDM";
 
 export interface DMPanelData {
     userId: number;
@@ -48,8 +49,12 @@ export class DMPanel extends MessagePanel {
 
     private async parseTextPayload(env: DmEnvelope, decryptedMessages: Message[]) {
         const plaintext = await decryptDm(env, this.dmData!.publicKey);
-        const isAuthor = env.senderId !== this.dmData!.userId;
-        const username = isAuthor ? this.currentUser.currentUser?.username ?? "You" : this.dmData!.username;
+        const username = formatDMUsername(
+            env.senderId, 
+            env.recipientId, 
+            this.currentUser.currentUser?.id!, 
+            this.dmData!.username
+        );
 
         // Try parse JSON payload { type: "text", data: { content, files?, reply_to_id? } }
         let content = plaintext;
@@ -168,6 +173,7 @@ export class DMPanel extends MessagePanel {
         });
     }
 
+
     // Handle incoming WebSocket DM messages
     async handleWebSocketMessage(response: DMWebSocketMessage): Promise<void> {
         if (response.type === "dmNew" && this.dmData) {