Common

export async function sleep(ms: number) {  return new Promise((resolve) => setTimeout(resolve, ms));}export async function requestPermission() {  if (!('Notification' in window)) {    console.warn('Current browser does not support Notification API');    return;  }  if (Notification.permission !== 'granted') {    try {      return await Notification.requestPermission();    } catch (error) {      console.error('requestPermission error:', error);      return 'denied';    }  }  return Notification.permission;}