fix: 유저생성 트랜잭션 커밋로직 추가

Author: 1117mg

src/main/java/com/climbup/climbup/auth/filter/JwtAuthenticationFilter.java

@@ -66,8 +66,11 @@ protected void doFilterInternal(HttpServletRequest request,
     private void authenticateUser(HttpServletRequest request, String token) {
         Long userId = jwtUtil.getUserId(token);
 
-        var user = userRepository.findById(userId)
-                .orElseThrow(() -> new UserNotFoundException(userId));
+    var user = userRepository.findById(userId)
+            .orElseThrow(() -> {
+                log.error("사용자 조회 실패: userId={}", userId);
+                return new UserNotFoundException(userId);
+            });
 
         UsernamePasswordAuthenticationToken authentication =
                 new UsernamePasswordAuthenticationToken(

src/main/java/com/climbup/climbup/auth/service/CustomOAuth2UserService.java

@@ -78,6 +78,10 @@ private User createUser(KakaoOAuth2UserInfo userInfo) {
 
         User savedUser = userRepository.save(user);
 
+        userRepository.flush();
+
+        log.info("새 사용자 생성 완료: id={}, kakaoId={}", savedUser.getId(), savedUser.getKakaoId());
+
         eventPublisher.publishEvent(new SignUpEvent(this, nickname, savedUser.getId()));
 
         return savedUser;