ci: free host ports before starting e2e infrastructure

Port 5432 was already in use after docker compose cleanup because a
system-level PostgreSQL service on the runner host holds the port.
Also kill any stray containers binding to 5432/9000/9001.

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

.gitea/workflows/ci.yml

@@ -83,8 +83,15 @@ jobs:
       - uses: actions/checkout@v4
 
       # ── Infrastructure ──────────────────────────────────────────────────────
-      - name: Cleanup leftover containers from previous runs
-        run: docker compose down --volumes --remove-orphans
+      - name: Cleanup leftover containers and free ports
+        run: |
+          docker compose down --volumes --remove-orphans || true
+          # Stop system-level PostgreSQL if present (host service can occupy port 5432)
+          sudo systemctl stop postgresql || true
+          # Kill any remaining container still binding to our ports
+          for port in 5432 9000 9001; do
+            docker ps -q --filter "publish=$port" | xargs -r docker stop || true
+          done
 
       - name: Start DB and MinIO
         run: docker compose up -d db minio create-buckets