Creates a dated row in a local registry with enough context to act on it cold. Two paths into it: the explicit one, where you ask for a reminder, and the autonomous one, where work just finished that carries a verification obligation and the check gets written without being asked.
Fires on “remind me to check X on Friday”, “follow up on Y by Tuesday”, or after any queued send, external ask, or background sync.
Writing the check is all it does. Executing it is a separate job, and it belongs to follow-up-runner.