- Use nullish coalescing (??) in api.js to support empty VITE_API_URL
- Set VITE_API_URL to backend's sslip.io Traefik domain
- Add sslip.io domains to CORS allowed origins
- Update FRONTEND_URL to sslip.io domain
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>