余额告警独立页面与多渠道通知：钉钉/飞书/企业微信/Bark，支持通知频率策略

- 告警设置拆分为独立页面，支持钉钉/飞书/企业微信/Bark/通用Webhook 多渠道
- 通知策略：低于阈值后按间隔重复提醒，达到最大次数停止，余额恢复自动重置
- 旧 webhook 配置自动迁移为通用渠道，渠道支持测试发送
- 优化告警话术：去商户ID展示、数字千分位格式化

backend/internal/handler/recharge.go

@@ -4,6 +4,7 @@ import (
 	"strconv"
 
 	"affiliate_dash/internal/middleware"
+	"affiliate_dash/internal/model"
 	"affiliate_dash/internal/pkg/response"
 	"affiliate_dash/internal/service"
 
@@ -113,9 +114,10 @@ func (h *RechargeHandler) GetAlertConfig(c *gin.Context) {
 }
 
 type alertConfigReq struct {
-	Enabled         bool   `json:"enabled"`
-	ThresholdPoints int64  `json:"threshold_points"`
-	WebhookURL      string `json:"webhook_url"`
+	Enabled               bool  `json:"enabled"`
+	ThresholdPoints       int64 `json:"threshold_points"`
+	NotifyIntervalMinutes int   `json:"notify_interval_minutes"`
+	MaxNotifications      int   `json:"max_notifications"`
 }
 
 // SaveAlertConfig PUT /api/merchant/recharge/alert-config
@@ -126,9 +128,10 @@ func (h *RechargeHandler) SaveAlertConfig(c *gin.Context) {
 		return
 	}
 	cfg, err := h.rechargeSvc.SaveAlertConfig(middleware.GetMerchantID(c), service.SaveAlertInput{
-		Enabled:         req.Enabled,
-		ThresholdPoints: req.ThresholdPoints,
-		WebhookURL:      req.WebhookURL,
+		Enabled:               req.Enabled,
+		ThresholdPoints:       req.ThresholdPoints,
+		NotifyIntervalMinutes: req.NotifyIntervalMinutes,
+		MaxNotifications:      req.MaxNotifications,
 	})
 	if err != nil {
 		response.BadRequest(c, err.Error())
@@ -137,6 +140,105 @@ func (h *RechargeHandler) SaveAlertConfig(c *gin.Context) {
 	response.OK(c, cfg)
 }
 
+// ListAlertChannels GET /api/merchant/alert-channels
+func (h *RechargeHandler) ListAlertChannels(c *gin.Context) {
+	list, err := h.rechargeSvc.ListAlertChannels(middleware.GetMerchantID(c))
+	if err != nil {
+		response.ServerError(c, err.Error())
+		return
+	}
+	response.OK(c, list)
+}
+
+type alertChannelReq struct {
+	ChannelType string `json:"channel_type" binding:"required"`
+	Name        string `json:"name"`
+	WebhookURL  string `json:"webhook_url"`
+	Server      string `json:"server"`
+	Key         string `json:"key"`
+	Enabled     *bool  `json:"enabled"`
+}
+
+func (r alertChannelReq) toInput() service.AlertChannelInput {
+	enabled := true
+	if r.Enabled != nil {
+		enabled = *r.Enabled
+	}
+	return service.AlertChannelInput{
+		ChannelType: r.ChannelType,
+		Name:        r.Name,
+		Enabled:     enabled,
+		Config: model.AlertChannelConfig{
+			WebhookURL: r.WebhookURL,
+			Server:     r.Server,
+			Key:        r.Key,
+		},
+	}
+}
+
+// CreateAlertChannel POST /api/merchant/alert-channels
+func (h *RechargeHandler) CreateAlertChannel(c *gin.Context) {
+	var req alertChannelReq
+	if err := c.ShouldBindJSON(&req); err != nil {
+		response.BadRequest(c, "参数错误：channel_type 必填")
+		return
+	}
+	channel, err := h.rechargeSvc.CreateAlertChannel(middleware.GetMerchantID(c), req.toInput())
+	if err != nil {
+		response.BadRequest(c, err.Error())
+		return
+	}
+	response.OK(c, channel)
+}
+
+// UpdateAlertChannel PUT /api/merchant/alert-channels/:id
+func (h *RechargeHandler) UpdateAlertChannel(c *gin.Context) {
+	id, _ := strconv.ParseUint(c.Param("id"), 10, 64)
+	if id == 0 {
+		response.BadRequest(c, "渠道 ID 无效")
+		return
+	}
+	var req alertChannelReq
+	if err := c.ShouldBindJSON(&req); err != nil {
+		response.BadRequest(c, "参数错误：channel_type 必填")
+		return
+	}
+	channel, err := h.rechargeSvc.UpdateAlertChannel(middleware.GetMerchantID(c), uint(id), req.toInput())
+	if err != nil {
+		response.BadRequest(c, err.Error())
+		return
+	}
+	response.OK(c, channel)
+}
+
+// DeleteAlertChannel DELETE /api/merchant/alert-channels/:id
+func (h *RechargeHandler) DeleteAlertChannel(c *gin.Context) {
+	id, _ := strconv.ParseUint(c.Param("id"), 10, 64)
+	if id == 0 {
+		response.BadRequest(c, "渠道 ID 无效")
+		return
+	}
+	if err := h.rechargeSvc.DeleteAlertChannel(middleware.GetMerchantID(c), uint(id)); err != nil {
+		response.ServerError(c, err.Error())
+		return
+	}
+	response.OK(c, nil)
+}
+
+// TestAlertChannel POST /api/merchant/alert-channels/:id/test
+func (h *RechargeHandler) TestAlertChannel(c *gin.Context) {
+	id, _ := strconv.ParseUint(c.Param("id"), 10, 64)
+	if id == 0 {
+		response.BadRequest(c, "渠道 ID 无效")
+		return
+	}
+	if err := h.rechargeSvc.TestAlertChannel(middleware.GetMerchantID(c), uint(id)); err != nil {
+		response.BadRequest(c, err.Error())
+		return
+	}
+	response.OK(c, nil)
+}
+
 // Upload POST /api/upload 上传凭证图片（multipart 字段名 file）。
 func (h *RechargeHandler) Upload(c *gin.Context) {
 	fileHeader, err := c.FormFile("file")