Sentinel command plane controls hardware writes with arbitration and safety

Sentinel's command plane enables writing to devices like heaters and door locks with safety mechanisms. The system uses dual-value points where 'reported' is the device state and 'desired' is the target system state, resolved through arbitration rules. Commands follow a state machine to verified outcomes, with fire-and-forget writes and automatic retry logic. The system prevents duplicate commands and manages claims that expire or suspend based on priority bands.