fix(ci): run ruff format, and record run 5 at 90% pair-correct

CI was red on `ruff format --check`: 23 files. I ran `ruff check` after every
change this session and never once ran `ruff format --check`, though CI runs
both. Lint passing is not formatting passing, and I treated one as evidence for
the other for the whole session.

Formatting applied. The full CI sequence now reproduces locally: format, lint,
mypy over 94 files, 735 tests, three gates byte-identical, compileall, and the
semantic job's 16 marked tests.

Also records run 5 of the pipeline measurement, which the vampi fix lifted as
predicted:

                       hunter (K=5)   pipeline (K=1)
  pair-correct              76.7%          90.0%
  leak                      12.3%           6.7%
  detection                    --          96.7%
  cost                     ~$0.69        $0.0068

27 of 30 pairs. Five runs, each step from a measurement contradicting an
assumption: 73.3 (no pipeline path) -> 73.3 (routing fixed, IDENTICAL, which
exposed the discarded verdict) -> 80.0 (residual question matched to its
arbiter) -> 86.7 (aiohttp settings) -> 90.0 (dominance question no longer
contradicting its own evidence).

One miss left: dsvpwa-dsvpwa-main, whose setting is an argparse --ssl default
rather than a security-setting call. Out of reach before the settings work and
still is; contorting the arbiter around one pair would be worse than the miss.

The caveat is recorded beside the number: 30 pairs of one slice, and the slice
iterated against all session. The +16% overfitting gap against vfc-js is why
contributor-scan Req 8.1/8.2 exist.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01T7XD7x5KonMdmGRkp63EQG

tests/test_subtraction_complete.py

@@ -53,8 +53,14 @@ def test_no_surviving_module_imports_a_removed_one() -> None:
 
 def test_the_removed_modules_are_gone_from_the_tree() -> None:
     assert not (SRC / "learning").exists(), "the learning package is removed; taxonomy/candidates/endpoint live under model/"
-    for relative in ("semantic/mechanisms.py", "semantic/variants.py", "semantic/variant_search.py",
-                     "semantic/prove_budget.py", "semantic/loo.py", "semantic/seed.py"):
+    for relative in (
+        "semantic/mechanisms.py",
+        "semantic/variants.py",
+        "semantic/variant_search.py",
+        "semantic/prove_budget.py",
+        "semantic/loo.py",
+        "semantic/seed.py",
+    ):
         assert not (SRC / relative).exists(), f"{relative} still exists"
 
 
@@ -69,8 +75,16 @@ def test_the_mechanism_lever_is_gone_from_the_retained_improve_loop() -> None:
     """
     evolve = (SRC / "improve" / "evolve.py").read_text()
     validator = (SRC / "improve" / "validator.py").read_text()
-    for symbol in ("MechanismEdit", "MechanismStore", "apply_mechanism_edits", "evaluate_mechanism_profiles",
-                   "propose_mechanism_edits", "validate_mechanism", "mechanism_store", "mechanism_candidates"):
+    for symbol in (
+        "MechanismEdit",
+        "MechanismStore",
+        "apply_mechanism_edits",
+        "evaluate_mechanism_profiles",
+        "propose_mechanism_edits",
+        "validate_mechanism",
+        "mechanism_store",
+        "mechanism_candidates",
+    ):
         assert symbol not in evolve, f"{symbol} survives in improve/evolve.py"
         assert symbol not in validator, f"{symbol} survives in improve/validator.py"
     assert "def run_improvement(" in evolve and "def propose_status_edits(" in evolve, "the rule-status loop must survive"