Fix TS2686 error in syncResultHandler

The file `src/hooks/sync/syncResultHandler.ts` was throwing a TS2686 error because it was using `React` without importing it, even though it's a module. This commit adds `import React from 'react';` to resolve the issue.

src/hooks/sync/syncResultHandler.ts

@@ -1,4 +1,5 @@
 
+import React, { useEffect } from 'react';
 import { SyncResult } from '@/utils/sync/data';
 import { toast } from '@/hooks/useToast.wrapper';
 import useNotifications from '@/hooks/useNotifications';
@@ -79,7 +80,7 @@ export const useSyncNotifications = () => {
   const { addNotification } = useNotifications();
   
   // 컴포넌트 마운트 시 알림 함수 설정
-  React.useEffect(() => {
+  useEffect(() => {
     setSyncNotificationAdder(addNotification);
     return () => setSyncNotificationAdder(null);
   }, [addNotification]);