Merges develop (closet hardening #826, strip_noise #785, lock #784) and
replaces every sub-feature in this PR with a correct, tested
implementation. Shippable now.
## 1. Real Okapi-BM25 (searcher.py)
The prior `_bm25_score()` hardcoded `idf = log(2.0)` for every term — it
was really a scaled TF, not BM25, and couldn't tell a discriminative
term from a generic one. Replaced with `_bm25_scores(query, documents)`
that computes proper IDF over the provided candidate corpus using the
Lucene smoothed formula `log((N - df + 0.5) / (df + 0.5) + 1)`. Well-
defined for re-ranking vector-retrieval candidates — IDF there measures
how discriminative each term is *within the candidate set*, exactly the
signal we want.
`_hybrid_rank` also fixed:
- Vector normalization is now absolute `max(0, 1 - dist)`, not
`1 - dist/max_dist` — adding/removing a candidate no longer reshuffles
the others.
- BM25 is min-max normalized within candidates (bounded [0, 1]).
- Closet path now re-ranks too (was previously returning closet-order
hits without hybrid scoring).
- `_hybrid_score` internal field stripped from output; `bm25_score`
exposed for debugging.
## 2. Entity metadata (miner.py)
- Reuses `_ENTITY_STOPLIST` from palace.py so sentence-starters like
"When", "After", "The" no longer land as entities (regression test
covers this).
- Known-entity registry is cached at module level, keyed by the
registry file's mtime — no more disk read per drawer.
- File handle now uses a context manager.
- Truncates the entity LIST (to 25) before joining — never splits a
name in the middle.
## 3. Diary ingest (diary_ingest.py)
- State file now lives at `~/.mempalace/state/diary_ingest_<hash>.json`,
keyed by (palace_path, diary_dir). No more pollution of the user's
content directory.
- Drawer IDs now hash `(wing, date_str)` — a user with personal + work
diaries on the same day no longer silently clobbers.
- Each day's upsert runs inside `mine_lock(source_file)` so concurrent
ingest from two terminals can't race.
- `force=True` now calls `purge_file_closets` before rebuild so
leftover numbered closets from a longer prior day don't orphan.
## 4. Tests (tests/test_closets.py)
Merged this PR's MineLock/Entity/BM25/Diary tests with develop's
hardened Build/Upsert/Purge/Rebuild/SearchClosetFirst tests. Added
specific regression tests for every fix above:
- entity stoplist applies (no "When/After/The")
- entity list capped before join (no partial tokens)
- registry cached by mtime (mock-verified zero re-reads)
- BM25 IDF downweights terms present in every doc (real BM25 evidence)
- hybrid rank absolute normalization stable against outliers
- diary state file outside user's diary dir
- diary wing-prefixed IDs prevent cross-wing date collisions
35/35 closet tests pass; full suite 743/743. ruff + format clean under
CI-pinned 0.4.x.
Igor Lins e Silva
32d7f4376b