refactor: 统一术语「成员」→「用户」，代码格式化

- 页面文案、注释、Toast 提示统一改为"用户"
- lefu 模块缩进格式化（空格→Tab）
- selectMemberDrawer 组件注释统一

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

miniprogram/pages/addMember/addMember.json

@@ -1,5 +1,5 @@
 {
-  "navigationBarTitleText": "添加成员",
+  "navigationBarTitleText": "添加用户",
   "usingComponents": {
     "select-member-drawer": "/components/selectMemberDrawer/selectMemberDrawer",
     "user-info-confirm-modal": "/components/userInfoConfirmModal/userInfoConfirmModal"