merge: develop + harden closet layer for production

Merges develop (#820 version sync, #785 strip_noise + NORMALIZE_VERSION,
#784 file locking) and addresses six concerns surfaced during PR review
of the closet feature:

1. Closet append-on-rebuild bug — upsert_closet_lines used to APPEND to
   existing closets (mismatched the doc's "fully replaced" promise). With
   NORMALIZE_VERSION rebuilds on develop, this would have stacked stale
   v1 topics on top of fresh v2 content forever. Fix:
   - Drop the read-and-append branch from upsert_closet_lines (now a pure
     numbered-id overwrite).
   - Add purge_file_closets(closets_col, source_file) helper that wipes
     every closet for a source file by where-filter.
   - process_file calls purge_file_closets before upsert on every mine,
     mirroring the existing drawer purge.

2. Searcher returned whole-file blobs from the closet path while the
   direct path returned chunk-level drawers. Refactored:
   - _extract_drawer_ids_from_closet parses the `→drawer_a,drawer_b`
     pointers out of closet documents.
   - _closet_first_hits hydrates exactly those drawer IDs (chunk-level),
     not collection.get(where=source_file) (which returned everything).
   - Same hit shape as direct-search path; both now carry matched_via.

3. max_distance was bypassed on the closet path. Now applied per-hit;
   when every closet candidate gets filtered, _closet_first_hits returns
   None and the caller falls through to direct drawer search.

4. Entity extraction caught sentence-starters like "When", "The",
   "After" as proper nouns. Added _ENTITY_STOPLIST (~40 common false
   positives + day/month names + role words). Real names like Igor /
   Milla still survive — covered by tests.

5. CLOSETS.md drifted from the code (claimed "replaced via upsert" but
   code appended; claimed BM25 hybrid that doesn't exist; claimed a
   10K char hydration cap that wasn't enforced). Rewritten to describe
   what actually ships, with explicit notes on the BM25 / convo-closet
   follow-ups.

6. Zero tests for ~250 lines. Added tests/test_closets.py with 17 cases:
   - build_closet_lines: pointer shape, header extraction, stoplist
     filtering (with regression case for "When/After/The"), real-name
     survival, fallback-line guarantee, drawer-ref slicing.
   - upsert_closet_lines: pure overwrite semantics (regression for the
     append bug), char-limit packing without splitting lines.
   - purge_file_closets: scoped to source_file, doesn't touch others.
   - End-to-end miner rebuild: re-mining a file with fewer topics fully
     purges leftover numbered closets from the larger first run.
   - _extract_drawer_ids_from_closet: parsing + dedup edge cases.
   - search_memories closet-first: fallback when empty, chunk-level
     hits with matched_via, no whole-file glue, max_distance enforced.

Merge resolutions: miner.py imports combined NORMALIZE_VERSION/mine_lock
from develop with the closet helpers from this branch. process_file
auto-merged cleanly (closet block sits inside develop's lock body).

724/724 tests pass. ruff + format clean under CI-pinned 0.4.x.

tests/test_closets.py

@@ -0,0 +1,316 @@
+"""
+test_closets.py — Tests for the closet (searchable index) layer.
+
+Covers:
+  * build_closet_lines — pointer-line shape, entity extraction, stoplist,
+    quote/header pickup, and the "always emit one line" guarantee.
+  * upsert_closet_lines — pure overwrite (no append), char-limit packing,
+    atomic-line guarantee.
+  * purge_file_closets — wipes prior closets so a re-mine starts clean.
+  * The end-to-end rebuild: re-mining a file fully replaces its closets,
+    including when the prior run produced more numbered closets.
+  * search_memories closet-first path — returns chunk-level hits parsed
+    from `→drawer_ids` pointers, falls back when closets are empty,
+    respects max_distance.
+"""
+
+from mempalace.miner import mine
+from mempalace.palace import (
+    CLOSET_CHAR_LIMIT,
+    build_closet_lines,
+    get_closets_collection,
+    purge_file_closets,
+    upsert_closet_lines,
+)
+from mempalace.searcher import _extract_drawer_ids_from_closet, search_memories
+
+
+# ── build_closet_lines ─────────────────────────────────────────────────
+
+
+class TestBuildClosetLines:
+    def test_emits_pointer_line_shape(self, tmp_path):
+        content = (
+            "# Auth rewrite\n\n"
+            "Decided we need to migrate to passkeys. "
+            "Built the prototype with WebAuthn. "
+            "Reviewed the API surface."
+        )
+        lines = build_closet_lines(
+            "/proj/auth.md",
+            ["drawer_proj_backend_aaa", "drawer_proj_backend_bbb"],
+            content,
+            wing="proj",
+            room="backend",
+        )
+        assert lines, "should always emit at least one line"
+        for line in lines:
+            assert "→" in line, f"line missing pointer arrow: {line!r}"
+            parts = line.split("|")
+            assert len(parts) == 3, f"expected topic|entities|→refs, got {line!r}"
+            assert parts[2].startswith("→")
+
+    def test_extracts_section_headers_as_topics(self):
+        content = "# First Header\nbody\n## Second Header\nmore body"
+        lines = build_closet_lines("/x.md", ["d1"], content, "w", "r")
+        joined = "\n".join(lines).lower()
+        assert "first header" in joined
+        assert "second header" in joined
+
+    def test_entity_stoplist_filters_sentence_starters(self):
+        # "When", "After", "The" repeat 3+ times — old code would index them
+        # as entities. New code's stoplist drops them.
+        content = (
+            "When the pipeline ran, the result was good. "
+            "When the user logged in, the token was issued. "
+            "After the migration, the latency dropped. "
+            "After the rollback, the latency rose. "
+            "The new flow is stable. The audit cleared."
+        )
+        lines = build_closet_lines("/x.md", ["d1"], content, "w", "r")
+        # Entities sit between the two pipes
+        entity_segments = [line.split("|")[1] for line in lines]
+        for seg in entity_segments:
+            tokens = set(seg.split(";")) if seg else set()
+            assert "When" not in tokens
+            assert "After" not in tokens
+            assert "The" not in tokens
+
+    def test_real_proper_nouns_survive_stoplist(self):
+        content = (
+            "Igor reviewed the diff. Milla wrote the spec. "
+            "Igor pushed the fix. Milla approved the PR. "
+            "Igor and Milla shipped together."
+        )
+        lines = build_closet_lines("/x.md", ["d1"], content, "w", "r")
+        entity_segments = [line.split("|")[1] for line in lines]
+        joined_entities = ";".join(entity_segments)
+        assert "Igor" in joined_entities
+        assert "Milla" in joined_entities
+
+    def test_emits_fallback_line_when_nothing_extractable(self):
+        # No headers, no action verbs, no quotes, no repeated capitalized words
+        content = "lorem ipsum dolor sit amet consectetur adipiscing elit"
+        lines = build_closet_lines("/x/notes.txt", ["d1"], content, "wing", "room")
+        assert len(lines) == 1
+        assert "wing/room/notes" in lines[0]
+        assert "→d1" in lines[0]
+
+    def test_pointer_references_first_three_drawers(self):
+        ids = [f"drawer_{i}" for i in range(10)]
+        lines = build_closet_lines("/x.md", ids, "# A\n# B", "w", "r")
+        assert all("→drawer_0,drawer_1,drawer_2" in line for line in lines)
+
+
+# ── upsert_closet_lines ───────────────────────────────────────────────
+
+
+class TestUpsertClosetLines:
+    def test_overwrites_existing_closet_does_not_append(self, palace_path):
+        col = get_closets_collection(palace_path)
+        base = "closet_test_room_abc"
+        meta = {"wing": "test", "room": "room", "source_file": "/x.md"}
+
+        # First mine — three short lines.
+        upsert_closet_lines(col, base, ["alpha|;|→d1", "beta|;|→d2", "gamma|;|→d3"], meta)
+        first = col.get(ids=[f"{base}_01"])
+        assert "alpha" in first["documents"][0]
+        assert "beta" in first["documents"][0]
+
+        # Second mine — entirely different lines. Must replace, not append.
+        upsert_closet_lines(col, base, ["delta|;|→d4", "epsilon|;|→d5"], meta)
+        second = col.get(ids=[f"{base}_01"])
+        doc = second["documents"][0]
+        assert "delta" in doc
+        assert "epsilon" in doc
+        assert "alpha" not in doc, "old closet line leaked into rebuild"
+        assert "beta" not in doc
+
+    def test_packs_into_multiple_closets_without_splitting_lines(self, palace_path):
+        col = get_closets_collection(palace_path)
+        base = "closet_pack_room_def"
+        meta = {"wing": "test", "room": "room", "source_file": "/y.md"}
+
+        # Build lines that approach but never exceed the limit.
+        line = "x" * 600  # well under CLOSET_CHAR_LIMIT
+        n_written = upsert_closet_lines(col, base, [line, line, line, line], meta)
+        # 4 lines @ 600+1 chars = 2404 — should pack into 2 closets (≤1500 each)
+        assert n_written == 2
+
+        for i in range(1, n_written + 1):
+            doc = col.get(ids=[f"{base}_{i:02d}"])["documents"][0]
+            # Every line is intact (never split mid-line)
+            for chunk in doc.split("\n"):
+                assert len(chunk) == 600, f"line was truncated in closet {i}"
+            # Closet stays under the cap
+            assert len(doc) <= CLOSET_CHAR_LIMIT
+
+
+# ── purge_file_closets ────────────────────────────────────────────────
+
+
+class TestPurgeFileClosets:
+    def test_deletes_only_the_targeted_source(self, palace_path):
+        col = get_closets_collection(palace_path)
+        col.upsert(
+            ids=["closet_a_01", "closet_b_01"],
+            documents=["a|;|→d1", "b|;|→d2"],
+            metadatas=[
+                {"source_file": "/keep.md", "wing": "w", "room": "r"},
+                {"source_file": "/drop.md", "wing": "w", "room": "r"},
+            ],
+        )
+        purge_file_closets(col, "/drop.md")
+
+        remaining_ids = set(col.get()["ids"])
+        assert "closet_a_01" in remaining_ids
+        assert "closet_b_01" not in remaining_ids
+
+
+# ── End-to-end rebuild via the project miner ──────────────────────────
+
+
+class TestMinerClosetRebuild:
+    def test_remine_replaces_closets_completely(self, tmp_path):
+        import yaml
+
+        project = tmp_path / "proj"
+        project.mkdir()
+        (project / "mempalace.yaml").write_text(
+            yaml.dump({"wing": "proj", "rooms": [{"name": "general", "description": "x"}]})
+        )
+        target = project / "doc.md"
+
+        # First mine — long content produces multiple numbered closets.
+        first_topics = "\n\n".join(f"# Topic {i}\n" + ("filler text " * 30) for i in range(15))
+        target.write_text(first_topics)
+        palace = tmp_path / "palace"
+        mine(str(project), str(palace), wing_override="proj", agent="test")
+
+        col = get_closets_collection(str(palace))
+        first_pass = col.get(where={"source_file": str(target)})
+        assert first_pass["ids"], "first mine should have written closets"
+        first_ids = set(first_pass["ids"])
+        assert any("topic 0" in (d or "").lower() for d in first_pass["documents"])
+
+        # Touch mtime so file_already_mined doesn't short-circuit, and
+        # rewrite with fewer topics (so the rebuild produces fewer closets
+        # than the first run).
+        import os
+        import time
+
+        target.write_text("# Only Topic Now\n" + ("short body " * 5))
+        new_mtime = os.path.getmtime(target) + 60
+        os.utime(target, (new_mtime, new_mtime))
+        time.sleep(0.01)  # ensure mtime delta is visible
+
+        mine(str(project), str(palace), wing_override="proj", agent="test")
+
+        col = get_closets_collection(str(palace))
+        second_pass = col.get(where={"source_file": str(target)})
+        second_docs = "\n".join(second_pass["documents"]).lower()
+        assert "only topic now" in second_docs
+        for i in range(15):
+            assert (
+                f"topic {i}\n" not in second_docs
+            ), f"stale 'Topic {i}' from first mine survived the rebuild"
+        # Numbered closets that existed only in the larger first run must be gone.
+        leftover = first_ids - set(second_pass["ids"])
+        for stale_id in leftover:
+            assert not col.get(ids=[stale_id])[
+                "ids"
+            ], f"orphan closet {stale_id} from larger first run survived purge"
+
+
+# ── _extract_drawer_ids_from_closet ───────────────────────────────────
+
+
+class TestExtractDrawerIds:
+    def test_parses_single_pointer(self):
+        assert _extract_drawer_ids_from_closet("topic|;|→drawer_x") == ["drawer_x"]
+
+    def test_parses_multiple_pointers_per_line(self):
+        line = "topic|ent|→drawer_a,drawer_b,drawer_c"
+        assert _extract_drawer_ids_from_closet(line) == [
+            "drawer_a",
+            "drawer_b",
+            "drawer_c",
+        ]
+
+    def test_dedupes_across_lines(self):
+        doc = "one|;|→drawer_a,drawer_b\ntwo|;|→drawer_b,drawer_c"
+        assert _extract_drawer_ids_from_closet(doc) == [
+            "drawer_a",
+            "drawer_b",
+            "drawer_c",
+        ]
+
+    def test_empty_doc_returns_empty(self):
+        assert _extract_drawer_ids_from_closet("") == []
+        assert _extract_drawer_ids_from_closet("no arrows here") == []
+
+
+# ── search_memories closet-first path ────────────────────────────────
+
+
+class TestSearchMemoriesClosetFirst:
+    def test_falls_back_to_direct_when_no_closets(self, palace_path, seeded_collection):
+        # seeded_collection populates only mempalace_drawers, not closets.
+        result = search_memories("JWT authentication", palace_path)
+        assert result["results"], "should still find drawer hits via fallback"
+        for hit in result["results"]:
+            assert hit.get("matched_via") == "drawer"
+
+    def test_closet_first_returns_chunk_level_hits(self, palace_path, seeded_collection):
+        # Build a closet that points at the JWT drawer specifically.
+        closets = get_closets_collection(palace_path)
+        closets.upsert(
+            ids=["closet_proj_backend_aaa_01"],
+            documents=["JWT auth tokens|;|→drawer_proj_backend_aaa"],
+            metadatas=[
+                {
+                    "wing": "project",
+                    "room": "backend",
+                    "source_file": "auth.py",
+                }
+            ],
+        )
+
+        result = search_memories("JWT authentication", palace_path)
+        assert result["results"], "closet-first search should hydrate the drawer"
+        top = result["results"][0]
+        assert top["matched_via"] == "closet"
+        # Must be the chunk-level drawer text, not a concatenation of every
+        # drawer in the file.
+        assert "JWT" in top["text"]
+        assert (
+            "Database migrations" not in top["text"]
+        ), "closet path should not glue unrelated drawers together"
+        assert "closet_preview" in top
+        assert "→drawer_proj_backend_aaa" in top["closet_preview"]
+
+    def test_max_distance_filters_closet_hits(self, palace_path, seeded_collection):
+        closets = get_closets_collection(palace_path)
+        closets.upsert(
+            ids=["closet_proj_backend_aaa_01"],
+            documents=["JWT auth tokens|;|→drawer_proj_backend_aaa"],
+            metadatas=[
+                {
+                    "wing": "project",
+                    "room": "backend",
+                    "source_file": "auth.py",
+                }
+            ],
+        )
+
+        # max_distance=0.001 is essentially "must match exactly". The closet
+        # path should reject everything and the caller falls back to direct
+        # search (which also filters with the same threshold).
+        result = search_memories(
+            "completely unrelated query about quantum gardening",
+            palace_path,
+            max_distance=0.001,
+        )
+        # Either no results, or every result respected the threshold.
+        for hit in result["results"]:
+            assert hit["distance"] <= 0.001