Fix: Resolve backend test hangs and ModuleNotFoundError in GitHub Actions

Fix: Replace deprecated libgl1-mesa-glx with libgl1 for Ubuntu 24.04 compatibility

Add root Dockerfile for Render Docker deployment

Fix: URL-encode database password special characters and allow all CORS hosts

Fix: Upgrade Next.js to ^15.1.7 to support stable React 19

Fix: Upgrade lucide-react to support React 19 peer dependencies

Clean project layout deployment