complete/uncomplete return a CompletionResult str subclass carrying
appended (decided with the write under the lock), so duplicate
concurrent calls fire one transition event; day-complete only
evaluates for an instance due today.
One refresh pass builds the whole entity snapshot: active children,
today's instances with derived open/done/missed states, per-child
presence via the PresenceEngine (records converted to model objects),
rollup counts, and the custody cycle day. Interval configurable via
the new update_interval option, default five minutes.
orchestrator-agent
overseer