Fix Gradle build directory cache for UP-TO-DATE incremental builds.

Cache project .gradle/ and root build/ (execution history + outputs), restore git mtimes after checkout, skip set-version when unchanged, and bump cache keys to v2 with build-jar restore fallback.

Co-authored-by: Cursor <cursoragent@cursor.com>

.github/actions/cache-gradle-build/action.yml

@@ -1,5 +1,5 @@
 name: Restore Gradle build directories
-description: Restore module build/ trees for faster CI Gradle jobs
+description: Restore project .gradle/, build/ trees for faster CI Gradle jobs
 
 inputs:
   scope:
@@ -21,11 +21,15 @@ runs:
       id: cache
       with:
         path: |
+          .gradle
+          build
           app/desktop/build
           app/shared/build
           app/android/build
           utils/shared/build
           utils/android/build
-        key: gradle-build-${{ runner.os }}-${{ runner.arch }}-v1-${{ inputs.scope }}-${{ hashFiles('gradle/libs.versions.toml', 'settings.gradle.kts', 'gradle.properties', 'app/desktop/build.gradle.kts', 'app/desktop/proguard-rules.pro', 'app/shared/build.gradle.kts', 'app/android/build.gradle.kts', 'utils/shared/build.gradle.kts', 'utils/android/build.gradle.kts') }}
+        key: gradle-build-${{ runner.os }}-${{ runner.arch }}-v2-${{ inputs.scope }}-${{ hashFiles('gradle/libs.versions.toml', 'settings.gradle.kts', 'gradle.properties', 'build.gradle.kts', 'app/desktop/build.gradle.kts', 'app/desktop/proguard-rules.pro', 'app/shared/build.gradle.kts', 'app/android/build.gradle.kts', 'utils/shared/build.gradle.kts', 'utils/android/build.gradle.kts') }}
         restore-keys: |
-          gradle-build-${{ runner.os }}-${{ runner.arch }}-v1-
+          gradle-build-${{ runner.os }}-${{ runner.arch }}-v2-${{ inputs.scope }}-
+          gradle-build-${{ runner.os }}-${{ runner.arch }}-v2-build-jar-
+          gradle-build-${{ runner.os }}-${{ runner.arch }}-v2-

.github/actions/restore-git-mtimes/action.yml

@@ -0,0 +1,12 @@
+name: Restore git mtimes
+description: Reset tracked file timestamps from git so Gradle incremental builds can be UP-TO-DATE after checkout
+
+runs:
+  using: composite
+  steps:
+    - name: Restore mtimes
+      shell: bash
+      run: |
+        set -euo pipefail
+        python3 -m pip install --disable-pip-version-check --quiet git-restore-mtime
+        python3 -m git_restore_mtime

.github/actions/save-gradle-build-cache/action.yml

@@ -1,5 +1,5 @@
 name: Save Gradle build directories
-description: Save module build/ trees after a Gradle build
+description: Save project .gradle/, build/ trees after a Gradle build
 
 inputs:
   primary-key:
@@ -14,6 +14,8 @@ runs:
       with:
         key: ${{ inputs.primary-key }}
         path: |
+          .gradle
+          build
           app/desktop/build
           app/shared/build
           app/android/build

.github/actions/set-version/action.yml

@@ -18,6 +18,12 @@ runs:
           VERSION_CODE=1
         fi
         GRADLE_FILE="build.gradle.kts"
+        CURRENT_NAME="$(sed -n 's/.*extra\["versionName"\] = "\([^"]*\)".*/\1/p' "$GRADLE_FILE" | head -n 1)"
+        CURRENT_CODE="$(sed -n 's/.*extra\["versionCode"\] = \([0-9]*\).*/\1/p' "$GRADLE_FILE" | head -n 1)"
+        if [[ "$CURRENT_NAME" == "$VERSION" && "$CURRENT_CODE" == "$VERSION_CODE" ]]; then
+          echo "versionName=$VERSION versionCode=$VERSION_CODE (unchanged)"
+          exit 0
+        fi
         sed -i.bak "s/extra\\[\"versionName\"\\] = \"[^\"]*\"/extra[\"versionName\"] = \"$VERSION\"/" "$GRADLE_FILE"
         sed -i.bak "s/extra\\[\"versionCode\"\\] = [0-9]*/extra[\"versionCode\"] = $VERSION_CODE/" "$GRADLE_FILE"
         rm -f "$GRADLE_FILE.bak"

.github/workflows/release.yml

@@ -80,10 +80,11 @@ jobs:
       FROMCHAT_PREBUILT_PROGUARD: "0"
     steps:
       - uses: actions/checkout@v5
-      - uses: ./.github/actions/setup-java-gradle
+      - uses: ./.github/actions/restore-git-mtimes
       - uses: ./.github/actions/set-version
         with:
           version: ${{ needs.resolve-version.outputs.version }}
+      - uses: ./.github/actions/setup-java-gradle
       - uses: ./.github/actions/cache-gradle-build
         id: gradle-build-cache
         with:
@@ -108,10 +109,11 @@ jobs:
     timeout-minutes: 30
     steps:
       - uses: actions/checkout@v5
-      - uses: ./.github/actions/setup-java-gradle
+      - uses: ./.github/actions/restore-git-mtimes
       - uses: ./.github/actions/set-version
         with:
           version: ${{ needs.resolve-version.outputs.version }}
+      - uses: ./.github/actions/setup-java-gradle
       - uses: ./.github/actions/cache-gradle-build
         id: gradle-build-cache
         with:
@@ -164,6 +166,10 @@ jobs:
     timeout-minutes: 60
     steps:
       - uses: actions/checkout@v5
+      - uses: ./.github/actions/restore-git-mtimes
+      - uses: ./.github/actions/set-version
+        with:
+          version: ${{ needs.resolve-version.outputs.version }}
       - name: Ensure ARM64 packaging JDK
         if: matrix.arch == 'arm64'
         shell: cmd
@@ -178,9 +184,6 @@ jobs:
           gradle-version: wrapper
           cache-read-only: true
           add-job-summary: on-failure
-      - uses: ./.github/actions/set-version
-        with:
-          version: ${{ needs.resolve-version.outputs.version }}
       - uses: ./.github/actions/cache-gradle-build
         id: gradle-build-cache
         with:
@@ -237,6 +240,10 @@ jobs:
     timeout-minutes: 60
     steps:
       - uses: actions/checkout@v5
+      - uses: ./.github/actions/restore-git-mtimes
+      - uses: ./.github/actions/set-version
+        with:
+          version: ${{ needs.resolve-version.outputs.version }}
       - uses: ./.github/actions/setup-java-gradle
         if: matrix.arch == 'x64'
         with:
@@ -246,9 +253,6 @@ jobs:
         if: matrix.arch == 'arm64'
         with:
           cache-read-only: "true"
-      - uses: ./.github/actions/set-version
-        with:
-          version: ${{ needs.resolve-version.outputs.version }}
       - uses: ./.github/actions/cache-gradle-build
         id: gradle-build-cache
         with:
@@ -310,12 +314,13 @@ jobs:
     timeout-minutes: 45
     steps:
       - uses: actions/checkout@v5
-      - uses: ./.github/actions/setup-java-gradle
+      - uses: ./.github/actions/restore-git-mtimes
-        with:
-          cache-read-only: "true"
       - uses: ./.github/actions/set-version
         with:
           version: ${{ needs.resolve-version.outputs.version }}
+      - uses: ./.github/actions/setup-java-gradle
+        with:
+          cache-read-only: "true"
       - uses: ./.github/actions/cache-gradle-build
         id: gradle-build-cache
         with:
@@ -361,13 +366,14 @@ jobs:
     timeout-minutes: 60
     steps:
       - uses: actions/checkout@v5
+      - uses: ./.github/actions/restore-git-mtimes
+      - uses: ./.github/actions/set-version
+        with:
+          version: ${{ needs.resolve-version.outputs.version }}
       - uses: ./.github/actions/setup-java-gradle
         with:
           cache-read-only: "true"
       - uses: android-actions/setup-android@v4
-      - uses: ./.github/actions/set-version
-        with:
-          version: ${{ needs.resolve-version.outputs.version }}
       - uses: ./.github/actions/cache-gradle-build
         id: gradle-build-cache
         with: