- Server device exposing CPU/RAM/GPU/temperature/battery sensors via
/api/v1/system/performance, plus last-restart timestamp (cached with
jitter threshold so the recorder doesn't see poll wobble) and version.
- Update entity backed by /api/v1/system/update — installs via
/apply, hides the install button when the server reports
can_auto_update=false.
- Sync-clock entities: reset button, speed number, running switch, and
the event listener now refreshes on entity_changed events too.
- Bump manifest to 0.4.0.
