🐛 CORS 오류 수정

- 서비스 코드를 수정하였습니다.

src/main/java/com/committers/snowflowerthon/committersserver/auth/config/AuthenticationUtils.java

@@ -14,7 +14,7 @@ public static String getNickname() {
         Authentication authentication = getAuthentication();
 
         if (authentication != null) {
-            return getCustomAuthenticationToken(authentication).getName();
+            return String.valueOf(getCustomAuthenticationToken(authentication).getName());
         }
         // 커스텀 필요
         throw new UsernameNotFoundException("Nickname not found in the current Authentication context");
@@ -25,7 +25,7 @@ public static Long getMemberId() {
         Authentication authentication = getAuthentication();
 
         if (authentication != null) {
-            return getCustomAuthenticationToken(authentication).getMemberId();
+            return Long.valueOf(getCustomAuthenticationToken(authentication).getMemberId());
         }
         // 커스텀 필요
         throw new UsernameNotFoundException("Member ID not found in the current Authentication context");
@@ -35,7 +35,7 @@ public static Role getRole() {
         Authentication authentication = getAuthentication();
 
         if(authentication != null) {
-            return getCustomAuthenticationToken(authentication).getRole();
+            return Role.valueOf(getCustomAuthenticationToken(authentication).getRole().toString());
         }
         // 커스텀 필요
         throw new UsernameNotFoundException("Role not found in the current Authentication context");