Run Firebase Emulator ownership tests in CI

.github/workflows/firebase-emulator-tests.yml

@@ -0,0 +1,35 @@
+name: MotorSignal Firebase Emulator Tests
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  firestore-rules:
+    name: Firestore ownership rules
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: firebase/emulator-tests
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Set up Node
+        uses: actions/setup-node@v6
+        with:
+          node-version: '22'
+          cache: npm
+          cache-dependency-path: firebase/emulator-tests/package-lock.json
+
+      - name: Install dependencies
+        run: npm install
+
+      - name: Run Firestore Emulator tests
+        run: npm run test:emulator