Enable Gradle configuration and build caches

.github/workflows/android-tests.yml

@@ -25,6 +25,11 @@ jobs:
         uses: gradle/actions/setup-gradle@v4
         with:
           gradle-version: "9.5.0"
+          # Optional: persists the Gradle configuration cache across runs when
+          # a GRADLE_ENCRYPTION_KEY secret exists; harmless when unset. Safe
+          # here: test runs have no keystore, so their configuration cache
+          # contains no signing data (unlike Cut Release, which never sets this).
+          cache-encryption-key: ${{ secrets.GRADLE_ENCRYPTION_KEY }}
 
       - name: Run unit tests
         working-directory: android_app

.github/workflows/release.yml

@@ -53,6 +53,10 @@ jobs:
           distribution: temurin
           java-version: "17"
 
+      # No cache-encryption-key here on purpose: this job's configuration cache
+      # embeds the signing config, so it must never be persisted to the Actions
+      # cache. It is rebuilt each run (a few seconds); the dependency cache and
+      # the single combined Gradle invocation carry the speedup.
       - name: Set up Gradle
         uses: gradle/actions/setup-gradle@v4
         with:
@@ -87,13 +91,12 @@ jobs:
           ANDROID_RELEASE_KEY_ALIAS: ${{ secrets.ANDROID_RELEASE_KEY_ALIAS }}
           ANDROID_RELEASE_KEY_PASSWORD: ${{ secrets.ANDROID_RELEASE_KEY_PASSWORD }}
 
-      - name: Run unit tests
+      # One Gradle invocation for both: a failing test still aborts the release
+      # before anything is pushed, and the build pays the configuration phase
+      # and daemon start only once.
+      - name: Run tests and build signed release APK
         working-directory: android_app
-        run: gradle test
-
-      - name: Build signed release APK
-        working-directory: android_app
-        run: gradle assembleRelease
+        run: gradle test assembleRelease
 
       - name: Name release APK
         id: apk

CHANGELOG.md

@@ -1,6 +1,7 @@
 # Changelog
 
 ## Unreleased
+- Speed up Gradle builds locally and in CI: enable the configuration cache and build cache, and make Cut Release run the tests and the signed build in a single Gradle invocation.
 - Run CI tests only on pull requests: drop the push-to-master trigger, since everything reaching master goes through a tested PR or the Cut Release workflow, which runs the tests itself.
 
 ## v1.1.0 - 2026-07-03

android_app/gradle.properties

@@ -1 +1,8 @@
 android.useAndroidX=true
+
+# Cache Gradle's configuration phase and task outputs. In CI, setup-gradle
+# persists task outputs across runs; configuration-cache data is only persisted
+# when a GRADLE_ENCRYPTION_KEY secret is configured (it can contain signing
+# credentials, so it is never uploaded unencrypted).
+org.gradle.configuration-cache=true
+org.gradle.caching=true