feat: update docker-compose to use GHCR images and fix test failures

- Update docker-compose.yml to use ghcr.io/wikid82/caddyproxymanagerplus:latest
- Update docker-compose.dev.yml to use ghcr.io/wikid82/caddyproxymanagerplus:dev
- Fix backend test database isolation (remove shared cache mode)
- Add testConnection and enabledServers to useRemoteServers hook
- Fix frontend test assertions to wait for async state updates
- Wrap mutation assertions in waitFor for proper async handling

Backend tests: ✅ ALL PASSING (22 tests)
Frontend tests: ⚠️ 45/49 passing (4 useImport tests need mock refinement)

docker-compose.dev.yml

@@ -4,6 +4,7 @@ version: '3.9'
 
 services:
   app:
+    image: ghcr.io/wikid82/caddyproxymanagerplus:dev
     # Development: expose Caddy admin API externally for debugging
     ports:
       - "80:80"