[Refactor]: 기본 신용점수 50점 추가 (#242)

* [Refactor]: 기본 신용점수 50wja

* [Refactor]: 기본 신용점수 50점

Author: eunchan96

src/main/java/com/backend/domain/member/service/MemberService.java

@@ -37,6 +37,7 @@ public RsData<MemberSignUpResponseDto> signup(MemberSignUpRequestDto memberSignU
                 .phoneNumber(memberSignUpRequestDto.phoneNumber())
                 .address(memberSignUpRequestDto.address())
                 .authority("ROLE_USER")
+                .creditScore(50)
                 .build();
 
         Member savedMember = memberRepository.save(member);