Fix useCallback import error in image-input component

Fixed the import statement in webui/components/ui/image-input.tsx to properly import useCallback from React instead of importing it as a named import from React. This resolves the 'ReferenceError: useCallback is not defined' error that was occurring in the webui.

webui/components/ui/image-input.tsx

@@ -1,4 +1,4 @@
-import React, { useState, useRef, useEffect, useCallback } from 'react';
+import { useState, useRef, useEffect, useCallback } from 'react';
 import { Tabs, TabsContent, TabsList, TabsTrigger } from './tabs';
 import { Button } from './button';
 import { Input } from './input';
@@ -241,7 +241,7 @@ export function ImageInput({
 
   return (
     <div className={`image-input ${className}`}>
-      <Tabs value={state.mode} onValueChange={(value) => handleModeChange(value as 'file' | 'url')}>
+      <Tabs value={state.mode} onValueChange={(value: string) => handleModeChange(value as 'file' | 'url')}>
         <TabsList className="grid w-full grid-cols-2">
           <TabsTrigger value="file" disabled={disabled}>
             <Upload className="w-4 h-4 mr-2" />