chore: update deploy workflow to enable Docker BuildKit and add environment variables for authentication and database configuration

.gitea/workflows/deploy.yml

@@ -13,5 +13,11 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Deploy stack
+        env:
+          DOCKER_BUILDKIT: 1
+          COMPOSE_DOCKER_CLI_BUILD: 1
+          AUTH_SECRET: ${{ secrets.AUTH_SECRET }}
+          AUTH_URL: ${{ secrets.AUTH_URL }}
+          DATABASE_URL: ${{ secrets.DATABASE_URL }}
         run: |
           docker compose up -d