added close; fixed some issues

frontend/src/App.tsx

@@ -1,4 +1,5 @@
 import { useEffect, useState, useRef } from 'react';
+import { invoke } from '@tauri-apps/api/core';
 import { useEditorStore } from './store/editorStore';
 import VideoPlayer from './components/VideoPlayer';
 import TranscriptEditor from './components/TranscriptEditor';
@@ -18,6 +19,7 @@ import {
 } from 'lucide-react';
 
 const IS_ELECTRON = !!window.electronAPI;
+const IS_TAURI = !IS_ELECTRON && '__TAURI_INTERNALS__' in window;
 
 type Panel = 'ai' | 'settings' | 'export' | null;
 
@@ -45,6 +47,8 @@ export default function App() {
   useEffect(() => {
     if (IS_ELECTRON) {
       window.electronAPI!.getBackendUrl().then(setBackendUrl);
+    } else if (IS_TAURI) {
+      invoke<string>('get_backend_url').then(setBackendUrl).catch(console.error);
     }
   }, [setBackendUrl]);