重构组件结构，优化导入路径并移除不必要的组件，新增多个模态框组件以支持部门、角色、权限和用户管理功能

frontend/src/components/layout/Dashboard.vue

@@ -0,0 +1,38 @@
+<template>
+  <Headbar :changeAssistantVisible="changeAssistantVisible" :onSidebarToggle="toggleSidebar"></Headbar>
+  <Sidebar ref="sidebarRef" @menu-click="handleMenuClick"></Sidebar>
+  <div class="flex flex-row h-[calc(100vh-3.5rem)] mt-14">
+    <article class="flex-1 sm:ml-44 overflow-y-auto">
+      <RouterView></RouterView>
+    </article>
+    <Assistant v-if="isAssistantVisible"></Assistant>
+  </div>
+
+</template>
+
+<script setup lang="ts">
+import { ref } from "vue";
+import { RouterView } from "vue-router";
+import Assistant from "@/components/common/Assistant.vue";
+import Headbar from "./Headbar.vue";
+import Sidebar from "./Sidebar.vue";
+
+const isAssistantVisible = ref(false);
+const sidebarRef = ref();
+
+const changeAssistantVisible = () => {
+	isAssistantVisible.value = !isAssistantVisible.value;
+};
+
+const toggleSidebar = () => {
+	if (sidebarRef.value) {
+		sidebarRef.value.toggleSidebar();
+	}
+};
+
+const handleMenuClick = () => {
+	if (sidebarRef.value) {
+		sidebarRef.value.closeSidebar();
+	}
+};
+</script>