tenant: move admin member queries into service

backend/docs/swagger.yaml

@@ -185,6 +185,17 @@ definitions:
           退款原因：建议必填（由业务侧校验）；用于审计与追责。
         type: string
     type: object
+  dto.AdminTenantUserItem:
+    properties:
+      tenant_user:
+        allOf:
+        - $ref: '#/definitions/models.TenantUser'
+        description: TenantUser 租户成员关系记录。
+      user:
+        allOf:
+        - $ref: '#/definitions/models.User'
+        description: User 用户基础信息（用于展示 username 等）。
+    type: object
   dto.AdminTenantUserJoinResponse:
     properties:
       tenant_user:
@@ -1543,6 +1554,16 @@ paths:
         in: query
         name: page
         type: integer
+      - description: Role 按角色过滤（可选）：member/tenant_admin。
+        enum:
+        - member
+        - tenant_admin
+        in: query
+        name: role
+        type: string
+        x-enum-varnames:
+        - TenantUserRoleMember
+        - TenantUserRoleTenantAdmin
       - description: UserID 按用户ID过滤（可选）。
         in: query
         name: user_id
@@ -1557,7 +1578,7 @@ paths:
             - $ref: '#/definitions/requests.Pager'
             - properties:
                 items:
-                  $ref: '#/definitions/models.TenantUser'
+                  $ref: '#/definitions/dto.AdminTenantUserItem'
               type: object
       summary: 成员列表（租户管理）
       tags: