Optional ReadonlydetailLast observed type-specific detail (e.g. the reac type's honest link state, #217).
Optional ReadonlyerrorLast error message when status === 'error'.
Optional ReadonlypresentLast probed device presence (probeable types only; absent before the first probe).
Readonlystatus
The LIVE half of one adapter — status, never settings (rest-entity-map §5:
/adapter/{id}—/settings·/status(live, never persisted — the half conflated intoadapter.list)).