fix(rls): 收斂 API DB access context

apps/api/src/services/log_anomaly_detector.py

@@ -296,12 +296,11 @@ class LogAnomalyDetector:
         """
         try:
             from sqlalchemy.dialects.postgresql import insert as pg_insert
-            from src.db.base import get_session_factory
+            from src.db.base import get_db_context
             from src.db.models import LogClusterRecord
             from src.utils.timezone import now_taipei
 
-            factory = get_session_factory()
-            async with factory() as session:
+            async with get_db_context() as session:
                 stmt = pg_insert(LogClusterRecord).values(
                     cluster_id=cluster.cluster_id,
                     template=cluster.template,