chaim
7861b03f4b
When the n8n worker went down and recovered, multiple queued cron
executions fired scan-inbox in parallel. Each one saw the same file in
s3://insurance-kb/inbox/, each one called ingest_source — and the DB
ended up with duplicate source rows with identical checksums created in
the same second.
Guard scan-inbox with a session-level pg_try_advisory_lock (key "KBSC").
Concurrent callers return {skipped: true} immediately. The lock is
released in a finally block so a crash mid-scan still frees the next
scheduled run.
No schema change; no change to single-caller behavior.
Refs Task Master #2
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>