Filtered semantic search now keeps its recall. A find({ query, where }) that
pairs vector search with a metadata filter restricts the HNSW beam walk to the
matching candidates INSIDE the traversal (walk-all, collect-allowed) rather than
filtering the top-k afterward — so a query whose nearest vectors are all filtered
out still returns the best matches that DO pass the filter, instead of empty.
- JS HNSW search() honors the 8.0 `allowedIds: OpaqueIdSet | ReadonlySet<string>`
contract param (ANDs with candidateIds; ignores the opaque Buffer form it can't
decode — only a native provider consumes that).
- MetadataIndexProvider gains an OPTIONAL `getIdSetForFilter(filter): OpaqueIdSet`
producer — the native (cor) metadata index returns its roaring filter result as
a serialized buffer; the JS index does not implement it.
- find() forwards the matched universe to the vector walk: the opaque buffer
(zero id materialization) when the native producer is present, alongside the
materialized visibility-precise candidateIds for the JS index. Visibility stays
correct via the existing post-search hard filter.
Tested: JS recall/restriction/AND/opaque-ignore on the index directly, plus
find() forwarding the opaque universe through to the beam walk via a stubbed
native producer.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>