fix: avoid admin subscription binding regressions

backend/internal/service/admin_service.go

@@ -1282,6 +1282,9 @@ func (s *adminServiceImpl) AdminUpdateAPIKeyGroupID(ctx context.Context, keyID i
 		}
 		// 订阅类型分组：用户须持有该分组的有效订阅才可绑定
 		if group.IsSubscriptionType() {
+			if s.userSubRepo == nil {
+				return nil, infraerrors.InternalServer("SUBSCRIPTION_REPOSITORY_UNAVAILABLE", "subscription repository is not configured")
+			}
 			if _, err := s.userSubRepo.GetActiveByUserIDAndGroupID(ctx, apiKey.UserID, *groupID); err != nil {
 				if errors.Is(err, ErrSubscriptionNotFound) {
 					return nil, infraerrors.BadRequest("SUBSCRIPTION_REQUIRED", "user does not have an active subscription for this group")
@@ -1295,7 +1298,7 @@ func (s *adminServiceImpl) AdminUpdateAPIKeyGroupID(ctx context.Context, keyID i
 		apiKey.Group = group
 
 		// 专属标准分组：使用事务保证「添加分组权限」与「更新 API Key」的原子性
-		if group.IsExclusive {
+		if group.IsExclusive && !group.IsSubscriptionType() {
 			opCtx := ctx
 			var tx *dbent.Tx
 			if s.entClient == nil {