[WIP] Fix unauthorized error for /auth/signup API

[Copilot]

Thanks for asking me to work on this. I will get started on it and keep this PR's description up to date as I form a plan and make progress.

/auth/signup API를 다음과 같이 실행했어

{
"email": "hgjwilly@koreatech.ac.kr",
"password": "qwerty",
"passwordConfirm": "qwerty",
"name": "sdas"
}

근데 401 anauthorized가 발생해.
근데 다른 테스트 케이스에서는 회원가입이 잘 됨.

오류 원인을 찾아줘

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