feat(alert-center): 添加飞书Webhook通知渠道 + 告警引擎实时通知

- 后端: NotifyChannel 模型新增 feishu 类型, FeishuWebhookConfig
- 后端: TestNotifyChannel 真实发送飞书测试消息(文本格式)
- 后端: 告警引擎触发/恢复时自动发送飞书通知(sendFeishuAlert/sendFeishuRecovery)
- 后端: AlertEngine 新增 tcp_time_wait/tcp_close_wait/service_process 指标检测
- 后端: NetworkStatModel 新增 TCPCloseWait 字段
- 后端: QuickSetupRules 一键创建6条告警规则(CPU/内存/磁盘/TIME_WAIT/CLOSE_WAIT/进程)
- 后端: 注册 /alerts/quick-setup 路由
- 前端: AlertChannelDialog 新增飞书类型选项
- 前端: helpers 新增 getChannelIcon/getChannelTypeLabel 支持 feishu/dingtalk/wechat

backend/internal/api/handlers/alert_rules.go

@@ -1,6 +1,7 @@
 package handlers
 
 import (
+	"fmt"
 	"net/http"
 	"strconv"
 
@@ -272,3 +273,64 @@ func (h *AlertHandler) ToggleRule(c *gin.Context) {
 		Data:    rule,
 	})
 }
+
+// QuickSetupRules 一键创建测试告警规则（飞书Webhook测试用） // Logan.Li
+// @Summary 一键创建测试告警规则
+// @Tags 告警
+// @Router /alerts/quick-setup [post]
+func (h *AlertHandler) QuickSetupRules(c *gin.Context) {
+	type ruleDef struct {
+		Name      string  `json:"name"`
+		Metric    string  `json:"metric"`
+		Operator  string  `json:"operator"`
+		Threshold float64 `json:"threshold"`
+		Port      int     `json:"port,omitempty"`
+	}
+
+	var req struct {
+		Rules []ruleDef `json:"rules"`
+	}
+	c.ShouldBindJSON(&req)
+
+	// 默认规则：CPU 80%, 内存 80%, 磁盘 90%, TIME_WAIT 15000, CLOSE_WAIT 200, 端口Down, 进程检测
+	defaultRules := []ruleDef{
+		{Name: "CPU使用率", Metric: "cpu", Operator: ">", Threshold: 80},
+		{Name: "内存使用率", Metric: "mem", Operator: ">", Threshold: 80},
+		{Name: "磁盘使用率", Metric: "disk", Operator: ">", Threshold: 90},
+		{Name: "TIME_WAIT连接数", Metric: "tcp_time_wait", Operator: ">", Threshold: 15000},
+		{Name: "CLOSE_WAIT连接数", Metric: "tcp_close_wait", Operator: ">", Threshold: 200},
+		{Name: "进程异常退出", Metric: "service_process", Operator: "==", Threshold: 0},
+	}
+
+	rules := req.Rules
+	if len(rules) == 0 {
+		rules = defaultRules
+	}
+
+	created := 0
+	for _, def := range rules {
+		var existing models.AgentRule
+		h.db.Where("name = ?", def.Name).First(&existing)
+		if existing.ID > 0 {
+			continue
+		}
+		rule := models.AgentRule{
+			Name:      def.Name,
+			Metric:    def.Metric,
+			Operator:  def.Operator,
+			Threshold: def.Threshold,
+			Port:      def.Port,
+			Enabled:   true,
+		}
+		if err := h.db.Create(&rule).Error; err != nil {
+			continue
+		}
+		created++
+	}
+
+	c.JSON(http.StatusOK, models.Response{
+		Code:    200,
+		Message: fmt.Sprintf("已创建 %d 条告警规则", created),
+		Data:    gin.H{"created": created},
+	})
+}