- Add BEIJING_TZ constant in config.py - Replace all timezone.utc references across 11 files - Device-reported times, DB defaults, protocol sync all use Beijing time via [HAPI](https://hapi.run) Co-Authored-By: HAPI <noreply@hapi.run>
via HAPI (https://hapi.run) Co-Authored-By: HAPI <noreply@hapi.run>