Added tracking/capturing/restoration of audio playback state and position.

Harmonia.WinUI/ViewModels/PlayerViewModel.cs

@@ -225,6 +225,20 @@ public partial class PlayerViewModel : ViewModelBase
         _timer.Tick += TickTock;
 
         _dispatcherQueue = DispatcherQueue.GetForCurrentThread();
+
+        TryRestore();
+    }
+
+    private void TryRestore()
+    {
+        if (_audioPlayer.PlayingSong is null)
+            return;
+
+        Song = _audioPlayer.PlayingSong.Song;
+        Position = _audioPlayer.Position;
+        CurrentPosition = _audioPlayer.Position;
+
+        Task.Run(UpdateImage);
     }
 
     #region Event Handlers