- Remove three stale `# Use numeric file ID` / `# Pass file path` comments
in scanner.py. file_id is already normalized to str() above each call
site, so the inline comments mislead readers.
- Wrap `_backfill_doc_id_to_string` scroll loop + sentinel upsert in
try/except Exception. The qdrant_client singleton is assigned before
this migration runs, so a transient scroll failure was leaving the
process holding a usable client with int payloads permanently
unbackfilled until the next restart. Catch broadly, log ERROR with
exc_info, and return without writing the sentinel — next process
restart retries from scratch.
- Note `:memory:` mode behavior near the sentinel constants so future
readers don't read the every-start scroll as a bug.
- Document the two degraded-migration ERROR log signals in
docs/configuration.md so operators know when a clean restart is
required to recover indexing.
- Add unit test asserting scroll-time exceptions are logged and swallowed
without writing the sentinel.
Closes round-4 review feedback on PR #773.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
