// Obstacle.cs: BFS 기반 경로 탐색 및 복원
private void BuildBfsPath(Vector3 destination) {
    path.Clear(); pathIndex = 0;
    float cellSize = Mathf.Max(0.1f, bfsCellSize);
    int radiusCells = Mathf.Max(1, Mathf.CeilToInt(roamRadius / cellSize));
    Vector2Int start = WorldToCell(transform.position, cellSize);
    Vector2Int goal = WorldToCell(destination, cellSize);
    Queue<Vector2Int> queue = new Queue<Vector2Int>();
    Dictionary<Vector2Int, Vector2Int> previous = new Dictionary<Vector2Int, Vector2Int>();

    queue.Enqueue(start); previous[start] = start;
    while (queue.Count > 0) {
        Vector2Int current = queue.Dequeue();
        if (current == goal) break;
        for (int i = 0; i < directions.Length; i++) {
            Vector2Int next = current + directions[i];
            if (previous.ContainsKey(next) || next.sqrMagnitude > radiusCells * radiusCells) continue;
            previous[next] = current; queue.Enqueue(next);
        }
    }
}

// ObstacleSpawner.cs: targetTag(yumbabo) 오브젝트 상단에 장애물 생성
private void SpawnOnTarget(GameObject target) {
    if (target == null) return;
    Vector3 pos = GetTopPosition(target) + Vector3.up * spawnHeightOffset;
    if (minSpacing > 0f && !IsFarEnough(pos)) return; // 최소 거리 체크

    GameObject prefab = obstaclePrefabs[Random.Range(0, obstaclePrefabs.Length)];
    Quaternion rotation = randomYaw ? Quaternion.Euler(0f, Random.Range(0f, 360f), 0f) : Quaternion.identity;
    Transform parent = spawnedParent != null ? spawnedParent : transform;
    Instantiate(prefab, pos, rotation, parent);
    usedPositions.Add(pos);
}

// LunchRushPlayerController.cs: 장애물 피격 처리 및 체력 감소
public void HitObstacle(string obstacleName) {
    if (cleared || hitCooldownTimer > 0f) return;
    hitCooldownTimer = hitCooldown; // 무적 돌입
    slowTimer = slowDuration;       // 감속 디버프
    currentSpeed = Mathf.Max(startSpeed, currentSpeed - hitSpeedLoss);
    hearts = Mathf.Max(0, hearts - 1);
    heartUI?.SetHearts(hearts, maxHearts);

    if (followCamera == null) {
        followCamera = FindAnyObjectByType<FollowCamera>();
    }
    followCamera?.Shake(0.45f, hearts <= 0 ? 1.2f : 0.75f);
    if (hearts <= 0) Die(); 
}

// FollowCamera.cs: Perlin Noise 카메라 셰이크
private Vector3 GetShakeOffset() {
    if (shakeTimer <= 0f) return Vector3.zero;
    shakeTimer -= Time.deltaTime;
    float power = shakeStrength * (shakeTimer / shakeDuration);
    float x = (Mathf.PerlinNoise(Time.time * shakeFrequency, 0.17f) - 0.5f) * 2f;
    float y = (Mathf.PerlinNoise(0.41f, Time.time * shakeFrequency) - 0.5f) * 2f;
    return transform.right * x * power + transform.up * y * power;
}