_finish_time added datetime.now(timezone.utc) (fresh seconds/
microseconds every call) to the device's remaining-time duration, so the
returned timestamp differed at the sub-minute level on nearly every poll
even when remainingTime itself hadn't changed. The recorder logged a new
history/logbook entry each time, while the UI rounds the display down to
the minute, making repeated polls look like duplicate identical entries.
Round the result down to the minute so the entity only changes state
when the estimate actually shifts.
Jelle Lauwers
fe9a1128ea