Two worker-loop robustness fixes:
- Scan chunking: maybe_run_scan advances the library scan by at most one
scan_chunk (default scan.chunkSize=25 albums) per loop iteration, so a
large library no longer blocks job-claim/monitor for minutes-to-hours.
Progress persists in scan.inProgress/scan.cursor/scan.progress and is
resumable; scan.result (unchanged format) is written on completion.
- DB reconnect: wrap the loop body in `except psycopg.OperationalError`
(AdminShutdown subclasses it) to close the dead handle and reconnect via
wait_for_db() in-process, instead of crashing and relying on the
container restart policy. Verified via a backend-termination test.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Jonathan