- Created app_device_sync.py: background sync thread with connectivity-driven scheduling (5min online, 60sec backoff when offline)
- Server /api/device-config endpoints: GET for Pi device auth, POST for admin user auth
- Database migration adds config_version, owner_name, car_model, device_name, avatar_path to devices table
- Pi syncs config from server on network availability; offline-first design (loads from local JSON at startup)
- Settings UI fields read-only when server sync enabled
All 63 tests passing. Ready for testing with actual server connection.
Co-authored-by: Copilot <[email protected]>
