Enforce single terminal review decision per PR review run (Issue #211)

Reviewer agents could post probe APPROVE/REQUEST_CHANGES reviews while
testing lock paths, polluting PR audit trails. Add a review decision lock
seeded by gitea_resolve_task_capability(review_pr) that requires
gitea_mark_final_review_decision and final_review_decision_ready=True
before gitea_submit_pr_review performs a live mutation.

Add gitea_dry_run_pr_review for read-only submission validation,
gitea_authorize_review_correction for operator-approved fixes, and
assess_review_mutation_final_report for final-report proof. One live
review mutation per run unless correction is explicitly authorized.

tests/test_review_proofs.py

@@ -25,6 +25,7 @@ from review_proofs import (  # noqa: E402
     assess_controller_handoff,
     assess_inventory_completeness,
     assess_live_state_recheck,
+    assess_review_mutation_final_report,
     assess_role_boundary,
     assess_self_review_contamination,
     assess_sweep_evidence,
@@ -860,6 +861,55 @@ class TestControllerHandoff(unittest.TestCase):
         self.assertIn("issue #182", skill)
 
 
+class TestReviewMutationFinalReport(unittest.TestCase):
+    """Final reports must list exactly one live review mutation."""
+
+    LOCK_ONE = {
+        "live_mutations": [{"pr_number": 203, "action": "request_changes"}],
+        "correction_authorized": False,
+    }
+
+    def test_single_mutation_report_complete(self):
+        report = (
+            "Review complete on PR #203.\n"
+            "Review mutations: one request_changes on #203.\n"
+            "Review decision: request_changes."
+        )
+        result = assess_review_mutation_final_report(report, self.LOCK_ONE)
+        self.assertTrue(result["complete"])
+        self.assertFalse(result["downgraded"])
+
+    def test_missing_mutation_details_downgraded(self):
+        result = assess_review_mutation_final_report(
+            "Review complete. No details.", self.LOCK_ONE
+        )
+        self.assertFalse(result["complete"])
+        self.assertTrue(result["downgraded"])
+
+    def test_two_mutations_require_correction_explanation(self):
+        lock = {
+            "live_mutations": [
+                {"pr_number": 203, "action": "approve"},
+                {"pr_number": 203, "action": "request_changes"},
+            ],
+            "correction_authorized": True,
+            "correction_reason": "operator approved correcting mistaken approve",
+        }
+        incomplete = assess_review_mutation_final_report(
+            "Submitted approve then request_changes on #203.", lock
+        )
+        self.assertFalse(incomplete["complete"])
+
+        complete = assess_review_mutation_final_report(
+            "\n".join([
+                "Review mutations: approve (mistake), then request_changes (final).",
+                "Correction flow: operator approved correcting mistaken approve on PR #203.",
+            ]),
+            lock,
+        )
+        self.assertTrue(complete["complete"])
+
+
 class TestPRInventoryTrustGate(unittest.TestCase):
     """Issue #194: unit tests for the PR inventory trust gate."""