bench(harnessx-removal): deterministic baseline without the extra (task 1)

Equality script (design section 3) records suite outcomes, `ousast pairs --json`,
the python-vulnerable quick benchmark, one standard scan and `improve --dry-run`
from a frozen export with the harnessx extra absent and no model reachable.
Two independent records are byte-identical (determinism.json).

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01EmM1j46qgKMh3zqD1QMwEo

benchmarks/measurements/2026-09-30-harnessx-removal-baseline/scan/harness.json

@@ -0,0 +1,11 @@
+{
+ "contract_mode": "strict",
+ "model_roles": {
+  "hunter": null,
+  "patcher": null,
+  "ranker": null,
+  "verifier": null
+ },
+ "processor_versions": {},
+ "prompt_hashes": {}
+}