refactor: add JoinedRoomResponseDto missing field - playlist

src/backend/chatting-server/src/main/java/chattingserver/dto/response/JoinedRoomResponseDto.java

@@ -1,6 +1,7 @@
 package chattingserver.dto.response;
 
 import chattingserver.domain.chat.LastMessage;
+import chattingserver.domain.room.Playlist;
 import chattingserver.domain.room.User;
 import lombok.*;
 import java.util.List;
@@ -11,11 +12,12 @@
 @AllArgsConstructor
 @ToString
 public class JoinedRoomResponseDto {
-    private String roomId;
+    private String id;
     private String roomName;
     private long userCount;
-    private String thumbnailImage;
     private List<User> users;
     private UserListResponseDto playlistOwner;
+    private Playlist playlist;
+    private String thumbnailImage;
     private LastMessage lastMessage;
 }

src/backend/chatting-server/src/main/java/chattingserver/service/RoomService.java

@@ -58,12 +58,13 @@ public List<JoinedRoomResponseDto> findJoinedRoomsByUid(Long uid) {
                     .build();
 
             myRoomsDto.add(JoinedRoomResponseDto.builder()
-                    .roomId(roomId)
+                    .id(roomId)
                     .roomName(room.getRoomName())
-                    .thumbnailImage(room.getThumbnailImage())
-                    .users(room.getUsers())
                     .userCount(room.getUsers().size())
+                    .users(room.getUsers())
                     .playlistOwner(entityToResponseDtoConverter.convertUser(room.getPlaylistOwner()))
+                    .playlist(room.getPlaylist())
+                    .thumbnailImage(room.getThumbnailImage())
                     .lastMessage(lastMessage)
                     .build());
         }