The state-consistency worker now detects articles still flagged as
generating whose latest generation_task is already failed or completed
(with a version) and aligns the article status to the terminal task,
invalidating article caches on the way out. Adds supporting partial
indexes and switches UpdateGenerationTaskStatus to COALESCE started_at
and completed_at so partial status updates don't wipe the timestamps.
root
cbbed4b42c