add format convert support

src-tauri/src/commands.rs

@@ -77,7 +77,7 @@ pub async fn start_download(app: AppHandle, url: String, options: DownloadOption
             output_path: output_dir, 
             timestamp: chrono::Utc::now(),
             status: status.to_string(),
-            format: options.quality,
+            format: options.output_format,
         };
         
         let _ = storage::add_history_item(&app, item);