fix(Phase 4): 修正呼叫點遺漏傳入參數 — promql 和 sample_log

關聯節點檢查發現：
- dynamic_baseline_service.py: _save_baseline() 在 train_baseline() 中
  未傳入 promql/lookback_hours → PG 記錄無法追蹤訓練來源
- log_anomaly_detector.py: _save_new_cluster() 未傳入 sample_log →
  PG 記錄 LogCluster 時 sample_log 欄位為空

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/api/src/services/dynamic_baseline_service.py

@@ -138,7 +138,7 @@ class DynamicBaselineService:
                 return None
 
             state = self._fit_holt_winters(metric_name, datapoints)
-            await self._save_baseline(state)
+            await self._save_baseline(state, promql=promql, lookback_hours=lookback_hours)
             logger.info(
                 "baseline_trained",
                 metric=metric_name,

apps/api/src/services/log_anomaly_detector.py

@@ -187,7 +187,7 @@ class LogAnomalyDetector:
                 last_seen_at=now_str,
                 is_new=True,
             )
-            await self._save_new_cluster(log_cluster)
+            await self._save_new_cluster(log_cluster, sample_log=log_line)
 
             event = LogAnomalyEvent(
                 cluster_id=cluster_id,