/simplify-code finding: only one-shots carry a run_claim, yet the three
dispatch-failure paths called clear_run_claim unconditionally — each call
acquires _jobs_lock (blocking cross-process flock) and does a full
load_jobs read just to return False for any non-'once' job. The trigger
is exactly a failure storm (interpreter shutdown, EMFILE with N due
jobs): N serialized flock+file reads at the moment the process can least
afford I/O, all guaranteed no-ops for the majority job kind.
Gate at the call site on schedule.kind == 'once'; new mutation-checked
test proves recurring dispatch failures skip the claim I/O entirely.
9/9 tests green; ruff clean.
kshitij
baa1cfb89d