fix: auto-fix code issues (cron)

- 修复重复导入/字段
- 修复异常处理
- 修复PEP8格式问题
- 添加类型注解

backend/test_phase8_task8.py

@@ -10,15 +10,20 @@ InsightFlow Phase 8 Task 8: Operations & Monitoring Test Script
 4. 成本优化
 """
 
-from ops_manager import (
-    get_ops_manager, AlertSeverity, AlertStatus, AlertChannelType, AlertRuleType,
-    ResourceType
-)
+import json
 import os
 import sys
-import json
 from datetime import datetime, timedelta
 
+from ops_manager import (
+    AlertChannelType,
+    AlertRuleType,
+    AlertSeverity,
+    AlertStatus,
+    ResourceType,
+    get_ops_manager,
+)
+
 # Add backend directory to path
 backend_dir = os.path.dirname(os.path.abspath(__file__))
 if backend_dir not in sys.path: