chore: add CI workflow to gate pushes to main

Author: ace42588

.github/workflows/ci.yml

@@ -0,0 +1,48 @@
+name: CI
+
+on:
+  pull_request:
+  push:
+    branches: [main]
+
+concurrency:
+  group: ci-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  checks:
+    runs-on: ubuntu-latest
+    timeout-minutes: 45
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: "17"
+
+      - name: Setup Gradle
+        uses: gradle/actions/setup-gradle@v4
+
+      - name: Write google-services.json
+        env:
+          GOOGLE_SERVICES_JSON: ${{ secrets.GOOGLE_SERVICES_JSON }}
+        run: |
+          if [ -n "$GOOGLE_SERVICES_JSON" ]; then
+            printf '%s' "$GOOGLE_SERVICES_JSON" > app/google-services.json
+          else
+            cp app/google-services.json.example app/google-services.json
+          fi
+
+      - name: ktlint
+        run: ./gradlew ktlintCheck --no-daemon
+
+      - name: Unit tests
+        run: ./gradlew test --no-daemon
+
+      - name: Lint (app)
+        run: ./gradlew :app:lintDebug --no-daemon
+
+      - name: Assemble debug
+        run: ./gradlew :app:assembleDebug --no-daemon