Astro.response.headers must not be reassigned.

AstroResponseHeadersReassigned: Individual headers can be added to and removed from Astro.response.headers, but it must not be replaced with another instance of Headers altogether.

무엇이 잘못되었나요?

Astro.response로 사용 가능한 ResponseInit 객체의 headers 필드에 값이 설정될 때 발생합니다.