🗑️ remove: 불필요 코드 삭제

Author: LimKangHyun

backend/src/main/java/io/f1/backend/domain/game/app/GameService.java

@@ -79,6 +79,9 @@ public void handlePlayerReady(Long roomId, String sessionId) {
         Room room = findRoom(roomId);
 
         Player player = room.getPlayerSessionMap().get(sessionId);
+        if (player == null) {
+            throw new CustomException(RoomErrorCode.PLAYER_NOT_FOUND);
+        }
 
         toggleReadyIfPossible(room, player);
 

backend/src/main/java/io/f1/backend/domain/game/store/RoomRepository.java

@@ -15,6 +15,4 @@ public interface RoomRepository {
     List<Room> findAll();
 
     void removeRoom(Long roomId);
-
-    Optional<Player> findPlayerInRoomBySessionId(Long roomId, String sessionId);
 }

backend/src/main/java/io/f1/backend/domain/game/store/RoomRepositoryImpl.java

@@ -36,11 +36,6 @@ public void removeRoom(Long roomId) {
         roomMap.remove(roomId);
     }
 
-    @Override
-    public Optional<Player> findPlayerInRoomBySessionId(Long roomId, String sessionId) {
-        return findRoom(roomId).map(room -> room.getPlayerSessionMap().get(sessionId));
-    }
-
     // 테스트 전용 메소드
     public Room getRoomForTest(Long roomId) {
         return roomMap.get(roomId);