feat(alerts): 飞书通知支持 Web 界面配置(数据库存储+热更新)

1. 新增 notification_config 模型,飞书配置存数据库(单行id=1)
2. feishu_service 改为从数据库读配置,支持热更新,Web保存即生效
3. alerts.py 新增接口:
   - GET /alerts/notify/feishu/config 读配置(secret只返回是否已设)
   - PUT /alerts/notify/feishu/config 保存配置+热更新
   (status/test 同步改为走数据库配置)
4. 前端告警中心增加「飞书通知设置」弹窗:
   - 开关/Webhook/签名密钥/最低级别/类型白名单
   - 保存配置、发送测试按钮
5. alert_service.create_alert 推送时按数据库配置判断

配置无需改文件/重启,前端界面直接保存即生效。

backend/app/api/v1/alerts.py

@@ -185,11 +185,57 @@ def detect_offline_devices(db: Session = Depends(get_db)):
 
 # ========== 飞书告警通知 ==========
 
-@router.get("/notify/feishu/status", summary="获取飞书通知配置状态")
-def get_feishu_status():
-    """查看飞书通知是否已配置（不返回密钥等敏感信息）"""
+@router.get("/notify/feishu/config", summary="获取飞书通知配置")
+def get_feishu_config(db: Session = Depends(get_db)):
+    """读取飞书通知配置（Web 界面显示用，不返回 secret 原文只返回是否已设置）"""
+    from app.models.notification import NotificationConfig
+    row = NotificationConfig.get_singleton(db)
+    return {
+        "feishu_enabled": bool(row.feishu_enabled),
+        "feishu_webhook_url": row.feishu_webhook_url or "",
+        "feishu_secret_set": bool(row.feishu_secret),
+        "feishu_min_severity": row.feishu_min_severity or "warning",
+        "feishu_alert_types": row.feishu_alert_types or "",
+    }
+
+
+@router.put("/notify/feishu/config", summary="保存飞书通知配置")
+def update_feishu_config(
+    feishu_enabled: bool,
+    feishu_webhook_url: str = "",
+    feishu_secret: str = "",
+    feishu_min_severity: str = "warning",
+    feishu_alert_types: str = "",
+    db: Session = Depends(get_db),
+):
+    """保存飞书通知配置到数据库并热更新（无需重启后端）"""
+    from app.models.notification import NotificationConfig
+    row = NotificationConfig.get_singleton(db)
+    row.feishu_enabled = bool(feishu_enabled)
+    row.feishu_webhook_url = (feishu_webhook_url or "").strip()
+    # 仅当传入新 secret 时才覆盖（避免 UI 回显时清空已有 secret）
+    if feishu_secret:
+        row.feishu_secret = feishu_secret.strip()
+    row.feishu_min_severity = feishu_min_severity or "warning"
+    row.feishu_alert_types = (feishu_alert_types or "").strip()
+    db.commit()
+
+    # 热更新运行时的飞书服务
+    from app.services.feishu_service import reload_feishu_service
+    svc = reload_feishu_service(db)
+
+    return {
+        "message": "飞书通知配置已保存并生效",
+        "success": True,
+        "configured": svc.is_configured(),
+    }
+
+
+@router.get("/notify/feishu/status", summary="获取飞书通知运行状态")
+def get_feishu_status(db: Session = Depends(get_db)):
+    """查看飞书通知运行状态"""
     from app.services.feishu_service import get_feishu_service
-    svc = get_feishu_service()
+    svc = get_feishu_service(db)
     return {
         "enabled": svc.enabled,
         "configured": bool(svc.webhook_url),
@@ -202,14 +248,14 @@ def get_feishu_status():
 
 
 @router.post("/notify/feishu/test", summary="发送飞书测试告警")
-def test_feishu_notification():
+def test_feishu_notification(db: Session = Depends(get_db)):
     """发送一条测试告警到飞书，验证 webhook 配置是否正确"""
     from app.services.feishu_service import get_feishu_service
-    svc = get_feishu_service()
+    svc = get_feishu_service(db)
     if not svc.is_configured():
         raise HTTPException(
             status_code=400,
-            detail="飞书通知未启用或未配置 webhook。请在 backend/.env 设置 FEISHU_ENABLED=true 和 FEISHU_WEBHOOK_URL"
+            detail="飞书通知未启用或未配置 webhook。请在告警中心「飞书通知设置」中配置并开启"
         )
     ok = svc.send_alert({
         "alert_type": "new_device_detected",