feat: configure Coolify deployment for production

- Fix docker-compose.yml for production: use postgres:15-alpine, remove
  container names, remove postgres external port, set FRONTEND_URL to
  server IP, use empty VITE_API_URL for nginx proxy
- Add production server CORS origins to backend
- Add deploy job to GitHub Actions CI/CD pipeline

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -199,3 +199,17 @@ jobs:
       - name: Cleanup
         if: always()
         run: docker compose -f docker-compose.test.yml down -v
+
+  # Deploy to Coolify (only on main push)
+  deploy:
+    name: Deploy to Coolify
+    runs-on: ubuntu-latest
+    needs: [docker-build, integration]
+    if: github.ref == 'refs/heads/main' && github.event_name == 'push'
+
+    steps:
+      - name: Trigger Coolify Deployment
+        run: |
+          curl -X POST "${{ secrets.COOLIFY_WEBHOOK }}" \
+            -H "Authorization: Bearer ${{ secrets.COOLIFY_TOKEN }}" \
+            --fail --max-time 30