feat: 用户徽章与等级体系，积分经济管理重构

- 新增徽章系统：badge 服务与 handler、管理端配置页、BadgeChip/LevelBadge 展示组件
- 新增等级模型：model/level 及前端 levels 元数据
- 管理端经济模块拆分为 points/badges/levels 独立页面，EconomySettings 迁入设置
- 积分、签到、评论等服务适配等级与徽章逻辑

backend/service/chat.go

@@ -223,7 +223,7 @@ func (s *ChatService) attachPeers(views []RoomView, viewerID uint) {
 		return
 	}
 	var members []model.ChatRoomMember
-	s.db.Where("room_id IN ? AND user_id <> ?", directIDs, viewerID).Preload("User").Find(&members)
+	s.db.Where("room_id IN ? AND user_id <> ?", directIDs, viewerID).Preload("User").Preload("User.Badges.Badge").Find(&members)
 	peerByRoom := make(map[uint]*model.User, len(members))
 	for i := range members {
 		u := members[i].User
@@ -717,7 +717,7 @@ func (s *ChatService) ListMembers(userID, roomID uint, oversee bool) ([]model.Ch
 	var list []model.ChatRoomMember
 	err := s.db.Where("room_id = ?", roomID).
 		Order("CASE WHEN role = 'owner' THEN 0 WHEN role = 'admin' THEN 1 ELSE 2 END, created_at ASC").
-		Preload("User").
+		Preload("User").Preload("User.Badges.Badge").
 		Find(&list).Error
 	if err != nil {
 		return nil, err
@@ -1218,7 +1218,7 @@ func (s *ChatService) AdminListMessages(actor *Actor, page int, keyword, roomTyp
 	participantsByRoom := map[uint][]AdminChatParticipant{}
 	if roomType == model.ChatRoomTypeDirect && len(roomIDs) > 0 {
 		var members []model.ChatRoomMember
-		s.db.Where("room_id IN ?", roomIDs).Preload("User").Find(&members)
+		s.db.Where("room_id IN ?", roomIDs).Preload("User").Preload("User.Badges.Badge").Find(&members)
 		for i := range members {
 			name := members[i].User.Nickname
 			if name == "" {