refactor(SimpleFileUpload): 移除未使用的导入并优化代码结构

清理未使用的React hooks和antd组件导入，保持代码简洁

Cunkebao/src/components/Upload/SimpleFileUpload/index.tsx

@@ -1,7 +1,6 @@
-import React, { useRef, useState } from "react";
-import { Button, message } from "antd";
-import { FolderOutlined, LoadingOutlined } from "@ant-design/icons";
 import { uploadFile } from "@/api/common";
+import React, { useRef } from "react";
+import { message } from "antd";
 
 interface SimpleFileUploadProps {
   onFileUploaded?: (filePath: string) => void;