CI: cap Kotlin daemon heap (the real memory hog) + container swap off

Server report (20GB/4-core box) showed 3 Kotlin daemons at -Xmx5376m each + clang
swarm ~9GB thrashing swap. Cap kotlin.daemon.jvmargs and org.gradle.jvmargs to
1536m in gradle.properties, workers.max=2, no parallel. Container: --cpus=2
--memory=8g with swap disabled (--memory-swap==--memory) so it OOM-fails instead
of thrashing disk. Build now uses ~5GB.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.forgejo/workflows/build-apk.yml

@@ -22,9 +22,10 @@ jobs:
     # A purpose-built RN Android image (Android SDK + NDK + Node). Runner needs Docker.
     container:
       image: reactnativecommunity/react-native-android:latest
-      # Hard caps so the build can't starve the host: at most 2 CPUs and 6 GB RAM.
-      # Adjust to your box (e.g. --cpus=1 / --memory=4g on a smaller server).
-      options: --cpus=2 --memory=6g --memory-swap=6g
+      # Hard caps so the build can't starve the 20GB/4-core host: 2 CPUs, 8 GB RAM,
+      # and NO container swap (--memory-swap == --memory) so it OOM-fails cleanly
+      # instead of thrashing the disk with swap. With the JVM caps below it uses ~5 GB.
+      options: --cpus=2 --memory=8g --memory-swap=8g
     steps:
       - uses: actions/checkout@v4
 
@@ -47,6 +48,21 @@ jobs:
         working-directory: app
         run: CI=1 npx expo prebuild --platform android --no-install
 
+      # The real memory hog is the Kotlin daemon (default ~5.4 GB heap EACH, several
+      # spawned). Cap every JVM in gradle.properties so the build fits comfortably.
+      - name: Cap Gradle/Kotlin memory
+        working-directory: app/android
+        run: |
+          cat >> gradle.properties <<'PROPS'
+
+          # --- CI resource caps (host is small; don't thrash swap) ---
+          org.gradle.jvmargs=-Xmx1536m -XX:MaxMetaspaceSize=512m -Djava.net.preferIPv4Stack=true
+          org.gradle.workers.max=2
+          org.gradle.parallel=false
+          org.gradle.daemon=false
+          kotlin.daemon.jvmargs=-Xmx1536m
+          PROPS
+
       - name: Assemble signed release
         working-directory: app/android
         env:
@@ -54,16 +70,13 @@ jobs:
           BBP_UPLOAD_STORE_PASSWORD: ${{ secrets.ANDROID_KEYSTORE_PASSWORD }}
           BBP_UPLOAD_KEY_ALIAS: ${{ secrets.ANDROID_KEY_ALIAS }}
           BBP_UPLOAD_KEY_PASSWORD: ${{ secrets.ANDROID_KEY_PASSWORD }}
-          # Force IPv4 (runner container has no IPv6 -> dl.google.com unreachable) and
-          # cap the build JVM heap so it stays within the container's memory limit.
-          GRADLE_OPTS: "-Xmx3g -XX:MaxMetaspaceSize=768m -Djava.net.preferIPv4Stack=true"
-        # --max-workers=2 + no parallel project builds => at most ~2 concurrent tasks,
-        # so gradle/kotlin/C++ compiles don't fan out across every core on the host.
+          # Also cap the no-daemon launcher JVM (org.gradle.jvmargs targets the daemon).
+          GRADLE_OPTS: "-Xmx1536m -Djava.net.preferIPv4Stack=true"
+        # --max-workers=2 limits concurrent tasks; container --cpus=2 caps clang -j.
         run: >-
           ./gradlew :app:assembleRelease
           -PreactNativeArchitectures=arm64-v8a
-          --no-daemon --max-workers=2 -Dorg.gradle.parallel=false
-          -Djava.net.preferIPv4Stack=true
+          --no-daemon --max-workers=2
 
       # Self-contained publish via the Forgejo API (no external action to fetch).
       - name: Publish release + upload APK