feat(subscribe): add traffic limit rules and user traffic stats

- Add subscribe traffic_limit schema and migration\n- Support traffic_limit in admin create/update and list/details\n- Apply traffic_limit when building server user list speed limits\n- Add public user traffic stats API

internal/logic/admin/subscribe/createSubscribeLogic.go

@@ -34,6 +34,12 @@ func (l *CreateSubscribeLogic) CreateSubscribe(req *types.CreateSubscribeRequest
 		val, _ := json.Marshal(req.Discount)
 		discount = string(val)
 	}
+
+	trafficLimit := ""
+	if len(req.TrafficLimit) > 0 {
+		val, _ := json.Marshal(req.TrafficLimit)
+		trafficLimit = string(val)
+	}
 	sub := &subscribe.Subscribe{
 		Id:                0,
 		Name:              req.Name,
@@ -52,6 +58,7 @@ func (l *CreateSubscribeLogic) CreateSubscribe(req *types.CreateSubscribeRequest
 		NodeTags:          tool.StringSliceToString(req.NodeTags),
 		NodeGroupIds:      subscribe.JSONInt64Slice(req.NodeGroupIds),
 		NodeGroupId:       req.NodeGroupId,
+		TrafficLimit:      trafficLimit,
 		Show:              req.Show,
 		Sell:              req.Sell,
 		Sort:              0,

internal/logic/admin/subscribe/getSubscribeDetailsLogic.go

@@ -42,6 +42,12 @@ func (l *GetSubscribeDetailsLogic) GetSubscribeDetails(req *types.GetSubscribeDe
 			l.Logger.Error("[GetSubscribeDetailsLogic] JSON unmarshal failed: ", logger.Field("error", err.Error()), logger.Field("discount", sub.Discount))
 		}
 	}
+	if sub.TrafficLimit != "" {
+		err = json.Unmarshal([]byte(sub.TrafficLimit), &resp.TrafficLimit)
+		if err != nil {
+			l.Logger.Error("[GetSubscribeDetailsLogic] JSON unmarshal failed: ", logger.Field("error", err.Error()), logger.Field("traffic_limit", sub.TrafficLimit))
+		}
+	}
 	resp.Nodes = tool.StringToInt64Slice(sub.Nodes)
 	resp.NodeTags = strings.Split(sub.NodeTags, ",")
 	return resp, nil

internal/logic/admin/subscribe/getSubscribeListLogic.go

@@ -62,6 +62,12 @@ func (l *GetSubscribeListLogic) GetSubscribeList(req *types.GetSubscribeListRequ
 				l.Logger.Error("[GetSubscribeListLogic] JSON unmarshal failed: ", logger.Field("error", err.Error()), logger.Field("discount", item.Discount))
 			}
 		}
+		if item.TrafficLimit != "" {
+			err = json.Unmarshal([]byte(item.TrafficLimit), &sub.TrafficLimit)
+			if err != nil {
+				l.Logger.Error("[GetSubscribeListLogic] JSON unmarshal failed: ", logger.Field("error", err.Error()), logger.Field("traffic_limit", item.TrafficLimit))
+			}
+		}
 		sub.Nodes = tool.StringToInt64Slice(item.Nodes)
 		sub.NodeTags = strings.Split(item.NodeTags, ",")
 		// Handle NodeGroupIds - convert from JSONInt64Slice to []int64

internal/logic/admin/subscribe/updateSubscribeLogic.go

@@ -42,6 +42,12 @@ func (l *UpdateSubscribeLogic) UpdateSubscribe(req *types.UpdateSubscribeRequest
 		val, _ := json.Marshal(req.Discount)
 		discount = string(val)
 	}
+
+	trafficLimit := ""
+	if len(req.TrafficLimit) > 0 {
+		val, _ := json.Marshal(req.TrafficLimit)
+		trafficLimit = string(val)
+	}
 	sub := &subscribe.Subscribe{
 		Id:                req.Id,
 		Name:              req.Name,
@@ -60,6 +66,7 @@ func (l *UpdateSubscribeLogic) UpdateSubscribe(req *types.UpdateSubscribeRequest
 		NodeTags:          tool.StringSliceToString(req.NodeTags),
 		NodeGroupIds:      subscribe.JSONInt64Slice(req.NodeGroupIds),
 		NodeGroupId:       req.NodeGroupId,
+		TrafficLimit:      trafficLimit,
 		Show:              req.Show,
 		Sell:              req.Sell,
 		Sort:              req.Sort,