fix(ci): add PostgreSQL service container for integration tests

Integration tests require a real PostgreSQL database to connect to.
Added PostgreSQL 17 service container with proper health checks.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -82,6 +82,20 @@ jobs:
     name: Tests
     runs-on: ubuntu-latest
     needs: [lint, typecheck]
+    services:
+      postgres:
+        image: postgres:17
+        env:
+          POSTGRES_USER: payload
+          POSTGRES_PASSWORD: payload_test_password
+          POSTGRES_DB: payload_test
+        ports:
+          - 5432:5432
+        options: >-
+          --health-cmd pg_isready
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
@@ -120,7 +134,7 @@ jobs:
           PAYLOAD_PUBLIC_SERVER_URL: https://test.example.com
           NEXT_PUBLIC_SERVER_URL: https://test.example.com
           EMAIL_DELIVERY_DISABLED: 'true'
-          DATABASE_URI: postgresql://placeholder:placeholder@localhost:5432/placeholder
+          DATABASE_URI: postgresql://payload:payload_test_password@localhost:5432/payload_test
           CONSENT_LOGGING_API_KEY: ci-consent-api-key-placeholder
           IP_ANONYMIZATION_PEPPER: ci-anonymization-pepper-placeholder