extract_and_store dedups each extracted fact against the vector store
before the (owner-scoped) text fallback. The vector store is a single
shared ChromaDB collection storing only {"source": "memory"} — no
owner — and find_similar queries it with no owner filter, so it can
return a memory_id belonging to a different tenant. The old code
continue'd (skipped storing) on any vector hit without checking
ownership, so when ChromaDB is healthy (the common path) a user's
freshly-extracted fact was silently dropped because it was merely
semantically similar to another user's memory — the text fallback that
IS owner-scoped never ran. Gate the skip on the matched memory being
this user's own (or legacy unowned), mirroring the text dedup predicate;
cross-tenant or stale matches fall through. Same bug class as #1743.
28b296a712