* fix(db): respect vector extension config in per-bank index migration
Migration d5e6f7a8b9c0 hardcoded HNSW when creating per-bank partial
vector indexes, ignoring HINDSIGHT_API_VECTOR_EXTENSION. This caused
banks migrated from pre-v0.4.18 to get HNSW indexes even when
pgvectorscale (DiskANN) or vchord was configured.
- Fix the original migration to read the vector extension config
- Add migration a4b5c6d7e8f9 to detect and recreate mismatched indexes
(skipped entirely when extension is pgvector, since those are correct)
* chore: regenerate openapi.json for v0.4.22 version bump