refactor(components): 更新 SideBarMenu 组件

- 引入 ElMessage 组件，用于后续的消息提示功能
- 优化代码结构，为后续功能扩展做准备

biji-qianduan/src/components/home/SidebarMenu.vue

@@ -74,7 +74,7 @@
 
 <script setup>
 import { h } from 'vue';
-import { ElSubMenu, ElMenuItem, ElIcon, ElMessageBox, ElTooltip } from 'element-plus';
+import { ElSubMenu, ElMenuItem, ElIcon, ElMessageBox, ElTooltip, ElMessage } from 'element-plus';
 import { Folder, Delete, Edit, Plus, Fold, Expand, Setting, Lock, SwitchButton } from '@element-plus/icons-vue';
 import { useUserStore } from '@/stores/user';
 import { useRouter } from 'vue-router';