- #13: Critical — swap delete/write order in _complete_one (write new
vectors before deleting old ones) to prevent data loss on write failure
- #12: Add logger.warning() to 3 resume-skip except blocks so silent
re-embed fallbacks are observable
- #14: Add lightweight HNSW query probe to _assert_collections_healthy
- #11: Log collection query failures in merge_retrieve instead of silent
continue
- #16: Reuse provider across payloads in encode_paper_job — one creation
per worker per paper instead of per payload
