The completed event's was_on_time travels on the CompletionResult
(decided with the write) instead of re-reading latest state a racing
reversal could replace; unload clears coordinator listeners before
the database close.
The harness tracks entities per entry so a platform unload removes
exactly that entry's entities; lifecycle tests prove deactivated
children drop out on reload, reactivation restores the original
unique_ids, new children appear without disturbing existing ones,
and the restart equivalent restores live states.