Review fixes to the import-run framework (A1):
1. detect_revision ran outside the failure handler, so a failed revision probe
(the most likely external failure) escaped unrecorded — violating "every
attempt is recorded". Now the running row is created FIRST, then
detect_revision + last-revision lookup + stage + validate + promote all run
inside the same handler; the row converts to no_op when the revision is
unchanged. New test covers a detection exception → recorded failed + alert.
2. asyncio.CancelledError (BaseException, not caught by except Exception) left a
permanent running row on deploy/scheduler shutdown. Now caught explicitly:
best-effort mark failed, then re-raise the cancellation (never swallowed).
New test asserts the run is failed and the error re-propagates.
Full suite 682 passed.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>