The old per-device last_check timestamp was only persisted while a
device was consuming budget, so a stop/restart across days left stale
budgets. Check the state file mtime instead: if it predates today's 7 AM
and we're past 7 AM, the server was offline during the daily reset, so
give every device a fresh budget. Also drops the redundant 2-minute
reset window and the persisted last_check field.
- Curfew and budget exhaustion now use shared _shutdown_devices()
- All device turnoffs run in parallel via ThreadPoolExecutor
- Faster shutdown when multiple devices need to be turned off
- Float-based budget tracking with precise elapsed time calculation
- Curfew enforcement (devices turn off when blocked)
- Terminal TUI with live status refresh
- Parallel device checks using ThreadPoolExecutor
- Simplified config with time range format (e.g. '15:00-20:30')
- Optimistic UI updates for budget buttons
- Bug fixes: curfew shutdown, last_check reset on offline
