find() trusted the metadata index's returned ids: it loaded each id's entity
and returned it, checking only that the entity existed — never that it actually
matched the query. The indexes are acceleration structures; the loaded entity
is ground truth. A stale or cross-bucket index posting (e.g. an id left in a
field-value bucket by a delete or an `update({ field: undefined })`) therefore
surfaced an entity matching NEITHER the requested type NOR the where filter — a
production report saw a timeslot (NounType.Event) returned for
`find({ type: Person, where: { entityType: 'staff' } })`.
Add a single egress chokepoint after the result IIFE that re-validates every
result with `entityMatchesFind` (type/subtype/where/service/excludeVFS) — the
live-path mirror of the historical path's per-candidate check in db.ts. It
covers every find() branch (metadata, vector, text, proximity, graph) and
`similar()` (which delegates to find) in one place. A no-op on a healthy index;
on a corrupted one it drops the bad row instead of returning a phantom. Full
unit + integration gate green confirms the where re-validation is consistent
with the index (no valid rows dropped).
This is the brainy-side safety net. The durable corruption itself lives in the
metadata index that owns the query (the native provider when present) and is
addressed separately.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
