A task stuck in 'post_processing' past the cutoff was force-marked 'completed'
("assume it worked"). In a large batch, post-processing (AcoustID + quality +
import) is serialized and backs up, so tasks sit in post_processing while merely
QUEUED — then got falsely completed, showing as downloaded with no file on disk
(/Transfer empty).
Now: the cutoff is 30 min (was 5) so legit backlog isn't cut off, and when it
does fire the task is only completed if it actually produced a file
(final_file_path exists on disk) — otherwise marked failed (honest + retryable).
Applied at both stuck-detection sites (check_batch_completion + _v2).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
9af31c3706