note_embeddings becomes one row per chunk: PK (note_id, chunk_index), plus
chunk_text (what this vector actually encodes) and chunker_version. Migration
0077 clears the table — embeddings are derived (0067 precedent) and the old
whole-document rows are indistinguishable from single-chunk notes, so the
startup backfill regenerates the corpus at the new shape. The backfill is now
version-aware: a future shape change is a CHUNKER_VERSION bump that re-embeds
exactly the stale notes, not another wipe.
upsert_note_embedding takes (title, body) and chunks internally — one path
for the write path, the recurrence spawn and the backfill. The recurrence
spawn's own embed call is deleted outright: create_note already embeds via
embed_note (#2056), so the spawn was a second copy of the rule. An emptied
record now CLEARS its stale vectors instead of leaving them findable.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UaYUaouG9jjhATyuxCKrQs
Move semantic_search_notes off the full-table Python cosine scan onto a native
pgvector column: indexed ORDER BY embedding <=> :q LIMIT k (HNSW, cosine).
Migration 0067 enables the extension, converts the JSONB embedding column to
vector(384) (stale-dim rows dropped and regenerated by the startup backfill),
and builds the HNSW cosine index. Postgres image moves postgres:16-alpine ->
pgvector/pgvector:pg17 across prod, quickstart, and CI.
Scribe: project 2, milestone 93, task 1031.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Xz4j1H7pjYSjKsEpgcNH5E
bvandeusenandClaude Fable 5