fix(governance): collapse km slo fallback series

apps/api/src/services/governance_agent.py

@@ -409,7 +409,7 @@ class GovernanceAgent:
             "autonomy_rate": "sli:autonomy_rate:5m",
             "decision_accuracy": "sli:decision_accuracy:5m",
             "confidence_calibration": "sli:confidence_calibration:1h",
-            "km_growth_rate": "max(knowledge_entries_created_24h) or sli:km_growth_rate:24h",
+            "km_growth_rate": "max(knowledge_entries_created_24h) or max(sli:km_growth_rate:24h)",
         }
         # 硬紅線：低於此值必須告警（非軟性警告）
         hard_red_lines: dict[str, float] = {

apps/api/tests/test_governance_agent.py

@@ -695,6 +695,6 @@ class TestCheckSloCompliance:
         with patch("httpx.AsyncClient", return_value=client):
             result = await agent.check_slo_compliance()
 
-        assert "max(knowledge_entries_created_24h) or sli:km_growth_rate:24h" in client.queries
+        assert "max(knowledge_entries_created_24h) or max(sli:km_growth_rate:24h)" in client.queries
         assert result["km_growth_rate"]["status"] == "ok"
         assert result["km_growth_rate"]["value"] == 25

docs/adr/ADR-100-ai-autonomous-slo.md

@@ -112,7 +112,7 @@ sum(rate(approval_records_high_confidence_total[1h]))
 ```promql
 max(knowledge_entries_created_24h)
 or
-increase(knowledge_entries_total[24h])
+max(increase(knowledge_entries_total[24h]))
 ```
 
 **Recording rule**: `sli:km_growth_rate:24h`

ops/monitoring/slo-rules.yml

@@ -50,7 +50,7 @@ groups:
         expr: |
           max(knowledge_entries_created_24h)
           or
-          increase(knowledge_entries_total[24h])
+          max(increase(knowledge_entries_total[24h]))
 
       # -----------------------------------------------------------------------
       # Error Budget Recording Rules（輔助 Grafana 顯示）