fix: 修复createFolder方法未正确添加到Vue methods中的问题

问题: 点击"新建文件夹"按钮时控制台报错 "createFolder is not a function"
原因: 之前使用正则表达式添加方法时没有成功匹配,导致方法未被添加
修复: 手动在renameFile方法后面正确添加createFolder方法

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

frontend/app.js

@@ -858,6 +858,41 @@ handleDragLeave(e) {
       }
     },
 
+    // 创建文件夹
+    async createFolder() {
+      const folderName = this.createFolderForm.folderName.trim();
+
+      if (!folderName) {
+        this.showToast('error', '错误', '请输入文件夹名称');
+        return;
+      }
+
+      // 前端验证文件夹名称
+      if (folderName.includes('/') || folderName.includes('\\') || folderName.includes('..') || folderName.includes(':')) {
+        this.showToast('error', '错误', '文件夹名称不能包含特殊字符 (/ \\ .. :)');
+        return;
+      }
+
+      try {
+        const response = await axios.post(`${this.apiBase}/api/files/mkdir`, {
+          path: this.currentPath,
+          folderName: folderName
+        }, {
+          headers: { 'Authorization': `Bearer ${this.token}` }
+        });
+
+        if (response.data.success) {
+          this.showToast('success', '成功', '文件夹创建成功');
+          this.showCreateFolderModal = false;
+          this.createFolderForm.folderName = '';
+          await this.loadFiles(); // 刷新文件列表
+        }
+      } catch (error) {
+        console.error('[创建文件夹失败]', error);
+        this.showToast('error', '错误', error.response?.data?.message || '创建文件夹失败');
+      }
+    },
+
     confirmDeleteFile(file) {
       const fileType = file.isDirectory ? '文件夹' : '文件';
       const warning = file.isDirectory ? "\n注意：只能删除空文件夹！" : "";