pgmnemo v0.9.0

Theme

Token-economy correctness + recall performance + schema extension.
Five patches: budget counter fix, project_id scoping for navigate_locate,
NULL-embedding ghost-exclusion fix, content_type/blob_ref/doc_ref columns,
and recall_hybrid O(n) rewrite to bounded CTEs.

Fixed

• #1 — navigate_locate budget counter (#budget, #token-economy):
  token_budget_chars previously counted full length(lesson_text) but
  delivered only left(lesson_text, 50) as preview. Budget filled ~5x too
  fast. Fix: LEAST(length(lesson_text), 50) — counter now matches delivered
  payload. Behavioral change: callers with token_budget_chars=2000 will
  receive ~40 rows (previously ~8). The budget now counts preview characters
  (<=50 chars/row). Reduce budget proportionally to preserve prior result
  counts.

• #2 — ingest() NULL-embedding != ghost (#ghost, #ingest):
  All lessons passing quality gates (F1 min-length, F2 repetition, F3
  near-dup) now have verified_at = NOW() unconditionally. Previously,
  lessons without commit_sha/artifact_hash were ghost-excluded from
  recall. ingest() IS the verification gate; provenance tier still
  contributes to the aux ranking score but no longer gates visibility.

• #4 — recall_hybrid O(n) → O(k log n) (#recall, #performance):
  Rewrote single raw_candidates CTE into two bounded CTEs:
  vec_candidates (HNSW index scan, LIMIT GREATEST(k*4, ef_search)) and
  bm25_candidates (GIN index scan, LIMIT GREATEST(k*4, 40)).
  RRF window functions now operate over <=2×fetch_k rows, not n.
  Deterministic tie-breaker (f.id ASC) added to final ORDER BY.
  #4 inclusion gated on host BENCHMARK (Recall@10 >= 0.55, delta <5pp
  vs Python 2-phase, >=2000-row corpus). May revert to 0.9.1 by founder
  decision.

Added

• #1b — project_id_filter on navigate_locate (#navigate, #parity):
  New 5th parameter project_id_filter INT DEFAULT NULL. Scopes candidates
  to a single project using the existing B-tree index
  (pgmnemo_agent_lesson_project_idx). Parity with recall_hybrid which
  has had project_id_filter since v0.4.0. Old 4-arg signature is dropped
  in migration.

• #3 — agent_lesson content_type/blob_ref/doc_ref columns (#schema):
  Three nullable columns: content_type TEXT, blob_ref TEXT,
  doc_ref TEXT. Gates future per-type dispatch (#5) and typed expand (#6)
  when G1 bench passes (>=50% coverage + >=3 distinct content_type values).

Upgrade

ALTER EXTENSION pgmnemo UPDATE TO '0.9.0';

Breaking changes

None. All changes are additive (new parameter with DEFAULT, corrected budget
counter, new nullable columns). Existing callers are unaffected. However,
navigate_locate callers should be aware that budget accounting is now
correct — ~5x more IDs returned per equivalent budget.

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