feat: polish VR gameplay and sync tools

Assets/Script/DownloadManager.cs

@@ -8,7 +8,8 @@ public class DownloadManager : MonoBehaviour
 {
     [SerializeField] private string baseUrl = "http://whdwo798.synology.me/beatsaber";
 
-    private static string CacheRoot => Path.Combine(Application.temporaryCachePath, "beatsaber");
+    private static string CacheRoot => Path.Combine(Application.persistentDataPath, "beatsaber");
+    private static string LegacyCacheRoot => Path.Combine(Application.temporaryCachePath, "beatsaber");
 
     // ── Public API ───────────────────────────────────────────
 
@@ -38,20 +39,35 @@ public class DownloadManager : MonoBehaviour
             Directory.Delete(dir, recursive: true);
             Debug.Log($"[DownloadManager] 삭제: {songId}");
         }
+
+        string legacyDir = LegacySongDir(songId);
+        if (Directory.Exists(legacyDir))
+            Directory.Delete(legacyDir, recursive: true);
     }
 
     public void DeleteDifficulty(SongInfo song, string difficulty)
     {
+        TryMigrateLegacySong(song.id);
+
         string path = MapPath(song, difficulty);
         if (path != null && File.Exists(path))
             File.Delete(path);
+
+        string songDir = SongDir(song.id);
+        if (Directory.Exists(songDir) && Directory.GetFileSystemEntries(songDir).Length == 0)
+            Directory.Delete(songDir);
     }
 
     public bool IsSongDownloaded(string songId)
-        => File.Exists(AudioPath(songId));
+    {
+        TryMigrateLegacySong(songId);
+        return File.Exists(AudioPath(songId));
+    }
 
     public bool IsDifficultyDownloaded(SongInfo song, string difficulty)
     {
+        TryMigrateLegacySong(song.id);
+
         string path = MapPath(song, difficulty);
         return path != null && File.Exists(path);
     }
@@ -73,6 +89,8 @@ public class DownloadManager : MonoBehaviour
     private IEnumerator DownloadSongCoroutine(SongInfo song, string difficulty,
         Action<float> onProgress, Action onComplete, Action<string> onError)
     {
+        TryMigrateLegacySong(song.id);
+
         string songDir = Path.GetFullPath(SongDir(song.id));
         Directory.CreateDirectory(songDir);
 
@@ -157,4 +175,37 @@ public class DownloadManager : MonoBehaviour
 
     private static string SongDir(string songId)
         => Path.Combine(CacheRoot, songId);
+
+    private static string LegacySongDir(string songId)
+        => Path.Combine(LegacyCacheRoot, songId);
+
+    private static void TryMigrateLegacySong(string songId)
+    {
+        string sourceDir = LegacySongDir(songId);
+        string targetDir = SongDir(songId);
+
+        if (Directory.Exists(targetDir) || !Directory.Exists(sourceDir))
+            return;
+
+        CopyDirectory(sourceDir, targetDir);
+        Directory.Delete(sourceDir, recursive: true);
+        Debug.Log($"[DownloadManager] 기존 캐시를 영구 저장소로 이동: {songId}");
+    }
+
+    private static void CopyDirectory(string sourceDir, string targetDir)
+    {
+        Directory.CreateDirectory(targetDir);
+
+        foreach (string file in Directory.GetFiles(sourceDir))
+        {
+            string targetFile = Path.Combine(targetDir, Path.GetFileName(file));
+            File.Copy(file, targetFile, overwrite: true);
+        }
+
+        foreach (string dir in Directory.GetDirectories(sourceDir))
+        {
+            string targetSubDir = Path.Combine(targetDir, Path.GetFileName(dir));
+            CopyDirectory(dir, targetSubDir);
+        }
+    }
 }