The DKN cloud REST endpoint lags behind the unit for several seconds
after a write, even though the unit itself and the DKN app reflect
the change immediately. The previous 2.5s optimistic-overlay TTL
expired well before the cloud caught up, so the next coordinator
publish (REST poll or socket device-data push) carried stale values
and the HA UI reverted to the previous setting.
Extend the overlay TTL to 30s as a safety bound, and track the
underlying device key + expected device value alongside each overlay.
On every coordinator publish, clear overlays whose device key now
reports the expected value (cloud has confirmed). The TTL still
caps how long a silently-failed write can hold a wrong value.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>