修复(#71): 管理员订阅限速接口拒绝负数限速和非法 traffic_limit

- SpeedLimit 加 validate:"gte=0" 校验
- TrafficLimit 加 JSON 格式校验
- 新增单测覆盖负数限速和非法 JSON 场景

Co-authored-by: multica-agent <github@multica.ai>

internal/logic/admin/user/updateUserSubscribeLogic.go

@@ -39,22 +39,32 @@ func (l *UpdateUserSubscribeLogic) UpdateUserSubscribe(req *types.UpdateUserSubs
 	} else {
 		userSub.Status = 1
 	}
+	speedLimit := userSub.SpeedLimit
+	if req.SpeedLimit != nil {
+		speedLimit = *req.SpeedLimit
+	}
+	trafficLimit := userSub.TrafficLimit
+	if req.TrafficLimit != nil {
+		trafficLimit = *req.TrafficLimit
+	}
 
 	err = l.svcCtx.UserModel.UpdateSubscribe(l.ctx, &user.Subscribe{
-		Id:          userSub.Id,
-		UserId:      userSub.UserId,
-		OrderId:     userSub.OrderId,
-		SubscribeId: req.SubscribeId,
-		StartTime:   userSub.StartTime,
-		ExpireTime:  time.UnixMilli(req.ExpiredAt),
-		Traffic:     req.Traffic,
-		Download:    req.Download,
-		Upload:      req.Upload,
-		Token:       userSub.Token,
-		UUID:        userSub.UUID,
-		Status:      userSub.Status,
-		NodeGroupId: userSub.NodeGroupId,
-		GroupLocked: userSub.GroupLocked,
+		Id:           userSub.Id,
+		UserId:       userSub.UserId,
+		OrderId:      userSub.OrderId,
+		SubscribeId:  req.SubscribeId,
+		StartTime:    userSub.StartTime,
+		ExpireTime:   time.UnixMilli(req.ExpiredAt),
+		Traffic:      req.Traffic,
+		Download:     req.Download,
+		Upload:       req.Upload,
+		SpeedLimit:   speedLimit,
+		TrafficLimit: trafficLimit,
+		Token:        userSub.Token,
+		UUID:         userSub.UUID,
+		Status:       userSub.Status,
+		NodeGroupId:  userSub.NodeGroupId,
+		GroupLocked:  userSub.GroupLocked,
 	})
 
 	if err != nil {