feat: 用户订阅显示节点分组名及限速起止时间

- UserSubscribe/UserSubscribeDetail 新增 node_group_id/node_group_name 字段
- 管理员查询用户订阅列表批量填充分组名
- 管理员查询单个订阅详情填充分组名
- ThrottleResult/UserSubscribeDetail 新增 throttle_start/throttle_end 字段
- 限速时返回限速窗口起止时间（秒级 Unix 时间戳）

Co-Authored-By: claude-flow <ruv@ruv.net>

internal/logic/admin/user/getUserSubscribeLogic.go

@@ -3,6 +3,7 @@ package user
 import (
 	"context"
 
+	"github.com/perfect-panel/server/internal/model/group"
 	"github.com/perfect-panel/server/internal/svc"
 	"github.com/perfect-panel/server/internal/types"
 	"github.com/perfect-panel/server/pkg/logger"
@@ -38,10 +39,33 @@ func (l *GetUserSubscribeLogic) GetUserSubscribe(req *types.GetUserSubscribeList
 		Total: int64(len(data)),
 	}
 
+	// 收集所有 node_group_id，批量查分组名
+	groupIdSet := make(map[int64]struct{})
+	for _, item := range data {
+		if item.NodeGroupId > 0 {
+			groupIdSet[item.NodeGroupId] = struct{}{}
+		}
+	}
+	groupNames := make(map[int64]string)
+	if len(groupIdSet) > 0 {
+		ids := make([]int64, 0, len(groupIdSet))
+		for id := range groupIdSet {
+			ids = append(ids, id)
+		}
+		var groups []group.NodeGroup
+		if err := l.svcCtx.DB.WithContext(l.ctx).Where("id IN ?", ids).Find(&groups).Error; err == nil {
+			for _, g := range groups {
+				groupNames[g.Id] = g.Name
+			}
+		}
+	}
+
 	for _, item := range data {
 		var sub types.UserSubscribe
 		tool.DeepCopy(&sub, item)
 		sub.Short, _ = tool.FixedUniqueString(item.Token, 8, "")
+		sub.NodeGroupId = item.NodeGroupId
+		sub.NodeGroupName = groupNames[item.NodeGroupId]
 		resp.List = append(resp.List, sub)
 	}
 	return