功能：告警级别体系统一为 0紧急/1重要/2普通/3轻微

更新 API 接口、Schema 验证、报告生成、企微通知的级别映射，
与前端和边缘端保持一致。

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/services/wechat_service.py

@@ -23,7 +23,7 @@ ALARM_TYPE_NAMES = {
 }
 
 # 告警级别映射
-ALARM_LEVEL_NAMES = {1: "提醒", 2: "一般", 3: "严重", 4: "紧急"}
+ALARM_LEVEL_NAMES = {0: "紧急", 1: "重要", 2: "普通", 3: "轻微"}
 
 
 class WeChatService:
@@ -210,7 +210,7 @@ class WeChatService:
             access_token = await self._get_access_token()
 
             type_name = ALARM_TYPE_NAMES.get(alarm_type, alarm_type)
-            level_name = ALARM_LEVEL_NAMES.get(alarm_level, "一般")
+            level_name = ALARM_LEVEL_NAMES.get(alarm_level, "普通")
 
             msg = {
                 "touser": "|".join(user_ids),
@@ -221,7 +221,7 @@ class WeChatService:
                     "task_id": alarm_id,
                     "source": {
                         "desc": "AI安防告警",
-                        "desc_color": 3 if alarm_level >= 3 else 0,
+                        "desc_color": 3 if alarm_level <= 1 else 0,
                     },
                     "main_title": {
                         "title": f"【{level_name}】{type_name}告警",
@@ -595,7 +595,7 @@ class WeChatService:
             return False
 
         type_name = ALARM_TYPE_NAMES.get(alarm_type, alarm_type)
-        level_name = ALARM_LEVEL_NAMES.get(alarm_level, "一般")
+        level_name = ALARM_LEVEL_NAMES.get(alarm_level, "普通")
         success = True
 
         # ---- 1. 发送告警截图（image 消息） ----