💡 Apple 인증 디버깅용 로그 추가

Author: cheshireHYUN

src/main/java/com/boggle_boggle/bbegok/oauth/client/impl/AppleOAuth2Client.java

@@ -54,6 +54,7 @@ public String requestAccessToken(String code) {
                         .with("redirect_uri", oAuthProperties.getApple().getRedirectUri()))
                 .retrieve()
                 .bodyToMono(AppleTokenResponse.class)
+                .doOnNext(raw -> log.info("[Apple] 응답 원문: {}", raw))
                 .block();
 
         this.cachedIdToken = tokenResponse.getIdToken();