fix: update openExternalUrl to use Tauri plugin shell for improved URL handling

src/app/utils/tauri.ts

@@ -5,8 +5,9 @@
 export const openExternalUrl = async (url: string): Promise<void> => {
   if (typeof window !== 'undefined' && (window as any).__TAURI__) {
     try {
-      const { openWithTauriShell } = await import('./tauriShell');
-      await openWithTauriShell(url);
+      // @ts-ignore
+      const { open } = await import(/* @vite-ignore */ '@tauri-apps/plugin-shell');
+      await open(url);
       return;
     } catch (err) {
       console.warn('Tauri shell.open failed, falling back to window.open:', err);