fix: alarm_id 时间戳改为北京时间

generate_alarm_id() 中 datetime.now(timezone.utc) 改为
datetime.now(timezone(timedelta(hours=8)))，与服务端时间一致。

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

core/result_reporter.py

@@ -9,7 +9,7 @@
 import json
 import logging
 import uuid
-from datetime import datetime, timezone
+from datetime import datetime, timezone, timedelta
 from typing import Any, Dict, List, Optional
 from dataclasses import dataclass, field
 
@@ -56,7 +56,7 @@ def generate_alarm_id(device_id: str) -> str:
     生成告警ID
     格式: edge_{device_id}_{YYYYMMDDHHmmss}_{6位uuid}
     """
-    timestamp = datetime.now(timezone.utc).strftime("%Y%m%d%H%M%S")
+    timestamp = datetime.now(timezone(timedelta(hours=8))).strftime("%Y%m%d%H%M%S")
     uid = uuid.uuid4().hex[:6]
     return f"edge_{device_id}_{timestamp}_{uid}"