feat(components): 新增创建分类和笔记对话框及头部组件

- 新增 CreateGroupDialog 组件用于创建分类
- 新增 CreateNoteDialog 组件用于创建笔记
- 新增 HomeHeader 组件用于显示主页头部信息
- 对话框组件使用 Element Plus 样式- 头部组件包含用户操作按钮和搜索功能

biji-qianduan/src/components/home/dialogs/PrivacyDialog.vue

@@ -0,0 +1,91 @@
+<template>
+  <el-dialog
+      :model-value="visible"
+      :title="title"
+      width="400px"
+      @close="handleClose"
+      :close-on-click-modal="false"
+  >
+    <div v-if="note">
+      <p>您确定要将笔记 <strong>"{{ note.title }}"</strong> {{ note.isPrivate === 1 ? '设为公开' : '设为私密' }}吗？</p>
+      <div class="privacy-explanation">
+        <el-icon><InfoFilled /></el-icon>
+        <span>{{ explanation }}</span>
+      </div>
+    </div>
+    <template #footer>
+      <el-button @click="handleClose">取消</el-button>
+      <el-button type="primary" @click="handleSubmit">确定</el-button>
+    </template>
+  </el-dialog>
+</template>
+
+<script setup>
+import { computed } from 'vue';
+import { ElMessage } from 'element-plus';
+import { updateMarkdown } from '@/api/CommonApi.js';
+import { InfoFilled } from '@element-plus/icons-vue';
+
+const props = defineProps({
+  visible: {
+    type: Boolean,
+    default: false,
+  },
+  note: {
+    type: Object,
+    default: null,
+  },
+});
+
+const emit = defineEmits(['update:visible', 'privacy-changed']);
+
+const title = computed(() => {
+  if (!props.note) return '';
+  return props.note.isPrivate === 1 ? '设为公开笔记' : '设为私密笔记';
+});
+
+const explanation = computed(() => {
+  if (!props.note) return '';
+  return props.note.isPrivate === 1 ? '公开笔记：所有用户都可以查看内容' : '私密笔记：只有登录用户才能查看内容';
+});
+
+const handleClose = () => {
+  emit('update:visible', false);
+};
+
+const handleSubmit = async () => {
+  if (!props.note) return;
+
+  try {
+    const newPrivacyStatus = props.note.isPrivate === 1 ? 0 : 1;
+    const payload = {
+      ...props.note,
+      isPrivate: newPrivacyStatus,
+    };
+
+    const updatedFile = await updateMarkdown(payload);
+    ElMessage.success(`笔记已${newPrivacyStatus === 1 ? '设为私密' : '设为公开'}`);
+    emit('privacy-changed', updatedFile);
+    handleClose();
+  } catch (error) {
+    ElMessage.error('修改笔记状态失败: ' + error.message);
+  }
+};
+</script>
+
+<style scoped>
+.privacy-explanation {
+  margin-top: 1rem;
+  padding: 0.75rem;
+  background-color: #f4f4f5;
+  border-radius: 4px;
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  color: #909399;
+}
+.dark-theme .privacy-explanation {
+  background-color: #2c2c3e;
+  color: #a9a9a9;
+}
+</style>