fix(governance): stop km healthcheck requeue

apps/api/tests/test_governance_dispatcher.py

@@ -285,6 +285,43 @@ class TestDispatchGovernanceEvent:
         mock_skip_cooldown.assert_not_awaited()
         mock_create.assert_awaited_once()
 
+    @pytest.mark.asyncio
+    async def test_knowledge_degradation_does_not_requeue_after_review_draft(self):
+        """同一 event 已有 Hermes review draft 後，不可反覆補 pending dispatch。"""
+        event = _make_governance_event(event_type="knowledge_degradation")
+        event.details = {
+            "remediation": {"next_action": "run_kb_growth_healthcheck"},
+            "ownership": {"lead_agent": "Hermes"},
+        }
+        succeeded_dispatch = MagicMock()
+        succeeded_dispatch.executor_type = "hermes_kb_growth_healthcheck"
+        succeeded_dispatch.dispatch_status = "succeeded"
+        succeeded_dispatch.decision_context = {
+            "workflow": {"current_stage": "waiting_owner_review"},
+            "worker_result": {"status": "draft_created"},
+        }
+
+        with (
+            patch(
+                "src.services.governance_dispatcher.get_active_for_event",
+                new=AsyncMock(return_value=None),
+            ),
+            patch(
+                "src.services.governance_dispatcher.list_by_event",
+                new=AsyncMock(return_value=[succeeded_dispatch]),
+            ) as mock_history,
+            patch(
+                "src.services.governance_dispatcher.create_dispatch",
+                new=AsyncMock(),
+            ) as mock_create,
+        ):
+            from src.services.governance_dispatcher import dispatch_governance_event
+            result = await dispatch_governance_event(event)
+
+        assert result is None
+        mock_history.assert_awaited_once_with("evt-001")
+        mock_create.assert_not_awaited()
+
     @pytest.mark.asyncio
     async def test_llm_failure_fallback_to_skip(self):
         """fusion adapter 拋 Exception → fallback skip，不寫 dispatch，返回 None。"""

apps/api/tests/test_hermes_kb_growth_worker.py

@@ -50,6 +50,7 @@ def test_km_review_payload_is_review_only():
     assert "agent:Hermes" in payload.tags
     assert "needs_owner_review" in payload.tags
     assert "dispatch:dispatch-001" in payload.tags
+    assert "governance_event:event-001" in payload.tags
     assert "writes_km_without_approval=false" in payload.content