Credibility pass: comments state constraints, not development history

A skeptical-cloner review flagged the patterns that read as AI-iteration
residue: test comments and section headers narrating the review process
that produced them, "legacy format" framing in a days-old repo, shadow
re-imports appended without reading file headers, one genuine machine
leftover (FIXTURE_CACHE = FIXTURE_CACHE), and a few register slips.
Every history-narrating comment is rewritten as the timeless invariant
it was guarding, test sections are grouped by behavior, function-local
imports are hoisted, and the README loses its one marketing clause and
heaviest dash runs. No behavior changes; 176 tests unchanged and green.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tests/test_extract.py

@@ -89,7 +89,7 @@ def test_parse_object_with_titles_and_unidentified():
     assert unidentified[0]["location"] == "top shelf, left of Catan"
 
 
-def test_parse_legacy_bare_array_still_works():
+def test_bare_array_response_shape_parses():
     text = '```json\n[{"title_raw": "Catan", "confidence": "high"}]\n```'
     titles, unidentified, _ = parse_vision_response(text)
     assert titles[0]["title_raw"] == "Catan"
@@ -274,8 +274,8 @@ def test_clean_photo_writes_empty_unidentified(tmp_path):
     assert json.loads(cfg.unidentified_path.read_text()) == {}
 
 
-def test_legacy_array_raw_cache_still_rebuilds(tmp_path):
-    """Raw files written before the unidentified feature are bare arrays."""
+def test_bare_array_raw_cache_rebuilds(tmp_path):
+    """A raw cache file may be a bare title array; it must still rebuild."""
     cfg = _cfg(tmp_path)
     cfg.photos_dir.mkdir()
     _write_image(cfg.photos_dir / "old.jpg")