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

tests/test_fusion.py

@@ -9,11 +9,10 @@ from openultrasast.findings import StaticFinding
 from openultrasast.fusion import (
     FusionDisposition,
     fuse_finding,
-    fuse_findings_dispatch,
+    fuse_findings,
     fusion_triggers,
     should_fuse,
 )
-from openultrasast.harness_ext import has_harnessx
 from openultrasast.verification import EvidenceLevel, VerificationResult, VerificationStatus
 
 
@@ -135,18 +134,10 @@ def test_dispatch_only_fuses_triggered_findings() -> None:
         _finding(finding_id="hot:app.py:3", severity="critical"),
         _finding(finding_id="cold:lib.py:9", severity="low", reachability="unknown"),
     ]
-    decisions = fuse_findings_dispatch(findings, [])
+    decisions = fuse_findings(findings, [])
     assert [d.finding_id for d in decisions] == ["hot:app.py:3"]
 
 
-def test_dispatch_records_degradation_when_llm_requested_but_extra_absent() -> None:
-    if has_harnessx():
-        pytest.skip("HarnessX extra installed; exercises the extra-absent degradation path")
-    decisions = fuse_findings_dispatch([_finding()], [], panel_model="gpt-4o", use_harnessx=True)
-    assert decisions and decisions[0].decision_source == "deterministic-reconciler"
-    assert any("fusion_llm_unavailable" in note for note in decisions[0].degradations)
-
-
 def test_decision_serializes_with_full_disclosure() -> None:
     decision = fuse_finding(_finding(), _verification(VerificationStatus.ACCEPTED, verified=True), ["severity:critical"])
     payload = json.loads(json.dumps(decision.to_dict()))