- Add site_id (Optional[UUID]) and site_name (Optional[str]) to backend DeviceResponse schema
- Include site fields in _build_device_response helper
- Add selectinload(Device.site) to _device_with_relations for eager loading
- Add site_id and site_name to frontend DeviceResponse interface
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>