Removes the TODO in Sync that left files static after their first embed.
Edits to brain/wiki/ and brain/knowledge/ now surface in subsequent
syncs without manual /backfill-embeddings calls.
Approach
- Store interface: KnownPaths → KnownPathsWithTime returning path →
updated_at. Callers compare against file mtime to detect edits.
- PGStore: SELECT path, updated_at FROM brain_embeddings.
- Sync groups known chunks by parent path and tracks the EARLIEST
updated_at per parent. A file is stale when its mtime is after that
oldest chunk's timestamp — any chunk older than the file means at
least one chunk hasn't been refreshed since the last edit.
- Stale-path rewrite: delete every old chunk for the parent (handles
"file shrunk → fewer chunks → orphan rows at higher #NNNN" cleanly),
then re-chunk + re-embed + re-upsert.
Tests
- New: TestSync_ReembedsFileWhenMtimeNewer — file mtime forced into the
future vs store updated_at; Sync deletes old chunk + upserts fresh one.
- New: TestSync_SkipsFileWhenMtimeOlder — file mtime backdated; Sync is
a no-op (no upserts, no deletes).
- Updated: stubStore.known is now map[string]time.Time. A zero value
resolves to a far-future sentinel so existing "skip if already known"
tests keep passing without per-test setup.
- pg_test renamed KnownPaths integration → KnownPathsWithTime; asserts
updated_at is non-zero and within 5s of insert wall-clock.
Backward compat
- brain_embeddings rows pre-dating this change carry valid updated_at
values (column was always populated via `DEFAULT now()` + ON CONFLICT
`updated_at = now()`). No migration needed. Live pod will start
re-embedding any file whose source has been edited since its chunks
were originally written.
Closes gitea/mathias/hyperguild#23.
815739758e