feat(kakao): 카카오 OAuth 응답 DTO 추가

Author: m-a-king

src/main/java/com/somemore/global/auth/oauth/dto/KakaoUserProfileResponseDto.java

@@ -0,0 +1,10 @@
+package com.somemore.global.auth.oauth.dto;
+
+import com.fasterxml.jackson.databind.PropertyNamingStrategies;
+import com.fasterxml.jackson.databind.annotation.JsonNaming;
+
+@JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
+public record KakaoUserProfileResponseDto(
+        String id // OAuth ID
+) {
+}