refactor(harnessx-removal): retire the HarnessX scan paths (task 5)

The standard scan now runs run_hunter_pool, verify_findings and the
deterministic fuse_findings directly; the HarnessX hunter orchestrator,
the LLM judge dispatcher (verify_judge.py, deleted with its test) and the
LLM fusion panels are gone, and so are their extra-absent degradations.
host_under_harnessx is dropped from stage_processors.

config: [models] verifier and [fusion] panel_model/decider_model raise
RetiredConfigError naming the plane replacement (the CLI prints it and
exits 2); a [harnessx] section loads with one warning and is otherwise
ignored. harness.json keeps "verifier": null. Tests that asserted the
fallback are renamed to the behaviour they assert; the module-audit
manifest drops verify_judge. Nothing outside the two modules deleted in
task 6 imports harness_ext or hunter_harness.

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

src/openultrasast/harness.py

@@ -180,7 +180,7 @@ def write_harness_config(
         model_roles={
             "ranker": config.models.ranker,
             "hunter": config.models.hunter,
-            "verifier": config.models.verifier,
+            "verifier": None,  # schema kept byte for byte; LLM verification runs on the plane
             "patcher": config.models.patcher,
         },
         processor_versions={processor.spec.name: processor.spec.version for processor in processors},