feat: Build and release per-architecture APKs (#550)

* feat: Build and release per-architecture APKs

This commit modifies the build process to generate separate APKs for different CPU architectures (arm64-v8a, x86_64) and a universal APK. This allows for smaller, optimized downloads for users and provides specific builds for platforms like Chromebooks.

Key changes:
- In `app/build.gradle.kts`, enables ABI splits to create `arm64-v8a`, `x86_64`, and `universal` APKs during the `assembleRelease` task.
- Updates the `release.yml` GitHub Actions workflow to rename and upload each of these APKs as distinct release assets.
- Removes the previous `arm64-v8a` only filter to allow for multi-architecture builds.

* feat: Allow manual triggering of Android CI workflow

This adds the `workflow_dispatch` event to the `android-build.yml` GitHub Actions workflow.

This change enables the Android CI pipeline to be run manually from the GitHub UI, in addition to the existing triggers for pushes and pull requests.

.github/workflows/android-build.yml

@@ -1,6 +1,7 @@
 name: Android CI
 
 on:
+  workflow_dispatch:
   push:
     branches: [ "main", "develop" ]
   pull_request:

.github/workflows/release.yml

@@ -38,17 +38,20 @@ jobs:
       - name: Grant execute permission for Gradlew
         run: chmod +x ./gradlew
 
-      - name: Build Release APK (with Tor)
+      - name: Build Release APKs (with architecture splits)
         run: ./gradlew assembleRelease --no-daemon --stacktrace
 
       - name: List APK files
         run: |
           echo "APK files built:"
-          find app/build/outputs/apk -name "*.apk" -type f
+          find app/build/outputs/apk/release -name "*.apk" -type f -exec ls -lh {} \;
 
-      - name: Rename APK
+      - name: Rename APKs for GitHub Release
         run: |
-          mv app/build/outputs/apk/release/app-release-unsigned.apk app/build/outputs/apk/release/bitchat-android.apk
+          cd app/build/outputs/apk/release
+          [ -f "app-arm64-v8a-release-unsigned.apk" ] && mv app-arm64-v8a-release-unsigned.apk bitchat-android-arm64.apk
+          [ -f "app-x86_64-release-unsigned.apk" ] && mv app-x86_64-release-unsigned.apk bitchat-android-x86_64.apk
+          [ -f "app-universal-release-unsigned.apk" ] && mv app-universal-release-unsigned.apk bitchat-android-universal.apk
 
       - name: DEBUG
         run: |
@@ -59,8 +62,8 @@ jobs:
           ls -all
           tree || ls -R
 
-      # Optional: Sign APK (requires secrets)
-      # - name: Sign APK
+      # Optional: Sign APKs (uncomment and configure secrets when ready)
+      # - name: Sign APKs
       #   uses: r0adkll/sign-android-release@v1
       #   with:
       #     releaseDirectory: app/build/outputs/apk/release
@@ -69,10 +72,10 @@ jobs:
       #     keyStorePassword: ${{ secrets.KEY_STORE_PASSWORD }}
       #     keyPassword: ${{ secrets.KEY_PASSWORD }}
 
-      - name: Upload APK as artifact
+      - name: Upload APKs as artifacts
         uses: actions/upload-artifact@v4
         with:
-          name: bitchat-android-apk-${{ github.ref_name }}
+          name: bitchat-android-release-${{ github.ref_name }}
           path: app/build/outputs/apk/release/*.apk
           retention-days: 30
           if-no-files-found: error
@@ -82,25 +85,23 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - name: Download APK artifact
+      - name: Download release artifacts
         uses: actions/download-artifact@v4
         with:
-          name: bitchat-android-apk-${{ github.ref_name }}
+          name: bitchat-android-release-${{ github.ref_name }}
           path: release
 
       - name: Create GitHub Release
         uses: softprops/action-gh-release@v2
         with:
           files: |
-            release/bitchat-android.apk
+            release/bitchat-android-arm64.apk
+            release/bitchat-android-x86_64.apk
+            release/bitchat-android-universal.apk
           name: Release ${{ github.ref_name }}
           body: |
-            ## bitchat Android Release
-
-            **bitchat-android.apk** (~15MB)
-            - Secure P2P messaging over Bluetooth mesh and Nostr
-            - Built-in Tor support (custom Arti build with 16KB page size)
-            - Compatible with Google Play requirements (Nov 2025+)
-            - Cross-platform compatible with iOS version
+            **bitchat-android-arm64.apk** - ARM64 (most phones)
+            **bitchat-android-x86_64.apk** - x86_64 (Chromebooks, tablets)
+            **bitchat-android-universal.apk** - All architectures (fallback)
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

app/build.gradle.kts

@@ -43,13 +43,20 @@ android {
                 getDefaultProguardFile("proguard-android-optimize.txt"),
                 "proguard-rules.pro"
             )
-            ndk {
-                // ARM64-only to minimize APK size (~5.8MB savings)
-                // Excludes x86_64 as emulator not needed for production builds
-                abiFilters += listOf("arm64-v8a")
-            }
         }
     }
+
+    // APK splits for GitHub releases - creates arm64, x86_64, and universal APKs
+    // AAB for Play Store handles architecture distribution automatically
+    splits {
+        abi {
+            isEnable = true
+            reset()
+            include("arm64-v8a", "x86_64")
+            isUniversalApk = true  // For F-Droid and fallback
+        }
+    }
+
     compileOptions {
         sourceCompatibility = JavaVersion.VERSION_1_8
         targetCompatibility = JavaVersion.VERSION_1_8