diff --git a/apps/api/src/services/decision_manager.py b/apps/api/src/services/decision_manager.py
index 63941918..684ca81c 100644
--- a/apps/api/src/services/decision_manager.py
+++ b/apps/api/src/services/decision_manager.py
@@ -2344,9 +2344,11 @@ class DecisionManager:
                     existing = []
                 existing.append(entry)
 
+                # asyncpg 不支援 :param::type 語法，改用 CAST(:param AS jsonb)
+                # 2026-04-16 Claude Sonnet 4.6: fix syntax error at or near ":"
                 await db.execute(
                     _sa_text(
-                        "UPDATE incidents SET decision_chain = :dc::json WHERE incident_id = :iid"
+                        "UPDATE incidents SET decision_chain = CAST(:dc AS jsonb) WHERE incident_id = :iid"
                     ),
                     {"dc": _json.dumps(existing), "iid": incident_id},
                 )
diff --git a/k8s/awoooi-prod/04-configmap.yaml b/k8s/awoooi-prod/04-configmap.yaml
index f78f1a77..93e0f32d 100644
--- a/k8s/awoooi-prod/04-configmap.yaml
+++ b/k8s/awoooi-prod/04-configmap.yaml
@@ -136,7 +136,10 @@ data:
   AIOPS_P4_LOG_ANOMALY: "true"
   AIOPS_P4_TREND_PREDICTOR: "true"
   AIOPS_P4_PROACTIVE_INSPECTOR: "true"
-  AIOPS_P4_SHADOW_MODE: "true"
+  # 2026-04-16 Claude Sonnet 4.6: 解除 shadow mode — 真實主動監控啟用
+  # 原因: baseline_anomalies/trend_breaches 皆 0，且 proactive_inspector 只寫 _last_report
+  # 行為改變: ProactiveAlert.shadow_mode=false → PreDecisionInvestigator 讀取後可觸發 Incident
+  AIOPS_P4_SHADOW_MODE: "false"
   AIOPS_P5_ENABLED: "true"
   AIOPS_P5_BLAST_RADIUS_CHECK: "true"
   AIOPS_P5_GITOPS_PR: "false"