Follow-ups on the #87259 salvage:
- cron/scheduler.py: the ledger-terminal reconciliation now requires the
terminal execution row's claimed_at to be >= the in-memory claim's
registration time (_running_since). Without this, the latest terminal
row for a recurring job is usually the PREVIOUS run's outcome — a fresh
claim in the try_register_running_job -> create_execution window (or a
finished run whose worker finally block hasn't released yet) would be
force-released and the job double-dispatched. Unparseable/missing
claimed_at fails closed to the age-based bound.
- cron/scheduler.py: take the _running_job_ids snapshot for the ledger
query under _running_lock — list() over a set concurrently mutated by
try_register/release_running_job can raise RuntimeError.
- tests: existing reconciliation tests updated to the claimed_at contract;
two new race-guard tests (previous-run terminal row never releases a
fresh claim; missing claimed_at fails closed). Mutation-verified:
removing the ownership guard fails both.
6370134bfe