When a staked pact day settles and money actually moves, that day's record is now locked for good. No check, un-check, or bulk edit can rewrite it — not even if the pact's stake is later reduced or removed.
The lock lives at two independent layers (the API says no, and the database itself refuses), so future features can't accidentally reopen history.
Behind the scenes: a new automated test suite now exercises the money paths end-to-end against a real database on every change — settlement, day-locking, and the delete safeguards.