Stop the checklist from quoting numbers no artifact carries

A review of the p2-1 record found seven places where the prose had drifted
away from the reports it cites. None were product defects; all were record
keeping, and record keeping is what a memory system is judged on.

The quantization row mis-transcribed nine latencies, and the two worst made
dimension truncation look twice as fast as the full scan when the report
measures six percent. The extrapolation table scaled latency by atoms and
bytes by vectors under one heading that named neither switch. The picture
index stats existed only in prose, so the harness now reads the index shape
off the artifact and times the encoder on a sample, which reproduces the
hand-timed build within seven percent. The dense arms named a store that
holds no vectors, so the report names the store the vectors came from and
refuses to run where a dense leg would rank an empty index.

The frozen baseline was migrated in place by the product CLI while the
picture index was built, so its pinned mtime, digest and schema version are
re-pinned and the step that moved it is named. The sqlite_vec import added
two mypy errors; the fix is the missing stub declaration, not an inline
ignore, and the count is back to the recorded baseline of twenty-four.

bench/tests/test_leg_check.py

@@ -37,6 +37,10 @@ def test_the_report_prints_every_arm_with_its_numbers(tmp_path: Path) -> None:
         "commit": "abcdef123456",
         "schema_version": 8,
         "store": "bench/runs/leg_check/data/ely_eye.sqlite",
+        "source_store": "bench/runs/dense_scale",
+        "dense_vectors": 153857,
+        "picture_index": {"path": "bench/runs/leg_check_index", "atoms": 53668, "dim": 512, "bytes": 109912192},
+        "encode_rate": {"pictures": 200, "seconds": 10.0, "per_second": 20.0},
         "probes": 300,
         "arms": [arm],
         "machine": {
@@ -53,4 +57,10 @@ def test_the_report_prints_every_arm_with_its_numbers(tmp_path: Path) -> None:
     assert "words only" in text
     assert "0.832" in text and "63.7" in text, "recall and latency must sit in the same row"
     assert "code" in text and "0.953" in text, "per-modality recall is where the picture legs show up"
+    assert (
+        "bench/runs/dense_scale" in text and "153,857 dense vectors" in text
+    ), "a dense arm must name the store its vectors came from, not imply the frozen baseline"
+    assert (
+        "53,668 atoms at 512 dimensions" in text and "44.7" in text
+    ), "the picture index needs its shape in the report, and its build cost derived from a measured rate"
     assert "abcdef123456" in text and "load_average" not in text