에러 본문:Error: The default Firebase app already exists. This means you called initializeApp() more than once without providing an app name as the second argument. In most cases you only need to call initializeApp() once. But if you do want to initialize multiple apps, pass a second argument to initializeApp() to give each app a unique name. 이미 초기화가 되어 있어서 할 수 없다는 내용입니다.Next.js 구조상 초기화 부분이 두번올 호출될 ..