Keep every file inside the rules the repo already wrote down

The 500-line rule and the one-line-comment rule were enforced only from
memory, so they drifted. bench/filesize_check.py now checks the budget on
every tracked source file, and it passes.

Split, with behaviour proven unchanged by comparing each moved function body
against HEAD byte for byte (53 training bodies, 21 benchmark bodies, 0
differences):

  db.py        503 -> 396   store_search.py     105
  bench/run.py 609 -> 351   query_set.py         80, report.py 211
  benchmarks.py 619 -> 424  benchmark_scoring.py 262
  training.py 1630 ->  94   training_{common,encode,metrics,datasets,lora,retrieval}

TrainingService stays as a thin facade for the CLI; the facade's parameter
lists are pinned against the module functions by inspect, which is what
catches a leaked self.

Deleted the eight top-level functions no file called, after fixing the scan
that had reported 201 false positives by skipping the defining file. The
v1/v2/v3 sweep found nothing to delete and says so: every remaining version
tag is an on-disk format marker, a migration step, a fixture name, or a
third-party model name.

Collapsed 39 multi-line comment blocks (86 lines) to one line each, keeping
the measured facts and error strings that justify the code.

269 tests pass; ruff clean; mypy 24 errors in 9 files against a 24-in-6
baseline, net zero; pyright 4, the same four HEAD measures.

backend/tests/test_proofs.py

@@ -26,8 +26,7 @@ from ely_eye.proofs.contradictions import (
 from ely_eye.proofs.table import render_table
 from ely_eye.schemas import MemoryOrigin
 
-# The replay question is fixed inside the suite, so the fixture memory has to answer it in words
-# the ranker can match.
+# The replay question is fixed inside the suite, so the fixture memory must answer it in words the ranker can match.
 PRD_MEMORY = "PRD requirements prove long context memory, HashHop proof, and adapter training."
 OTHER_KEYS = "PRD requirements also prove cache invalidation for HashHop proof and adapters."
 
@@ -95,8 +94,7 @@ def test_the_repository_check_fails_when_the_repository_never_reached_the_store(
 
 def test_the_replay_check_answers_only_from_the_cartridge_it_mounts(harness: Harness) -> None:
     inside = harness.remember(PRD_MEMORY)
-    # A second memory that answers the same question but stays out of the cartridge: an unmounted
-    # replay against the live store would have found it and called that a cartridge replay.
+    # A second memory answering the same question but outside the cartridge: an unmounted replay would have found it and called that a cartridge replay.
     harness.remember(OTHER_KEYS)
     cartridge_id = harness.cartridge("keys", [inside])
     manifest = next(
@@ -275,8 +273,7 @@ def test_the_hashhop_arena_marks_no_candidate_as_the_answer(harness: Harness, tm
 
     render_visual_hash_arena(tiles["top-left"], tiles, output)
 
-    # Every candidate box carries the same outline: a ring, an arrow, or a highlighted slot would
-    # tell a model the answer without reading a pixel of the source tile.
+    # Every candidate box carries the same outline: a ring, arrow or highlighted slot would give the answer without reading the tile.
     image = Image.open(output).convert("RGB")
     border_colors = {image.getpixel((box[0] + 2, box[1] + 40)) for box in boxes.values()}
     assert border_colors == {(180, 190, 205)}