fix for the download

client/src/app.tsx

@@ -56,7 +56,7 @@ export function App() {
     if (previewImage) {
       const link = document.createElement('a');
       link.href = previewImage;
-      link.download = 'modified_image.png';
+      link.download = 'result.webp';
       document.body.appendChild(link);
       link.click();
       document.body.removeChild(link);