fix(ci): split release.yaml sanity gradle calls to avoid OOM

The release workflow's ci-sanity job ran 'lint test assembleDebug' as
a single gradle invocation, which combined all three phases in one
JVM and exceeded the 2GB heap inside the gitea-actions docker
container ("Gradle build daemon disappeared unexpectedly"). Split
into three separate invocations matching ci.yaml - each gradle call
gets its own fresh 2GB JVM, well under the container's memory ceiling.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.gitea/workflows/release.yaml

@@ -37,8 +37,14 @@ jobs:
       - name: Grant execute permission for gradlew
         run: chmod +x ./gradlew
 
-      - name: Lint + tests + debug build (sanity)
-        run: ./gradlew lint test assembleDebug --no-daemon
+      - name: Lint
+        run: ./gradlew lint --no-daemon
+
+      - name: Unit tests
+        run: ./gradlew test --no-daemon
+
+      - name: Assemble debug APK (sanity)
+        run: ./gradlew assembleDebug --no-daemon
 
   build-and-deploy:
     needs: ci