fix: NowPlaying re-renders on StateChanged so WaveformVisualizer gets live track params when streaming starts

DeepDrftPublic.Client/Controls/NowPlaying.razor

@@ -1,4 +1,5 @@
 @using DeepDrftPublic.Client.Services
+@implements IDisposable
 
 @* Hero-right panel (owns the navy backdrop + clipping, formerly Home.razor's .hero-right wrapper). *@
 <div class="now-playing-panel">
@@ -39,4 +40,29 @@
 
 @code {
     [CascadingParameter] public IStreamingPlayerService? Player { get; set; }
+
+    private IStreamingPlayerService? _subscribedPlayer;
+
+    protected override void OnParametersSet()
+    {
+        if (Player != null && !ReferenceEquals(Player, _subscribedPlayer))
+        {
+            if (_subscribedPlayer != null)
+                _subscribedPlayer.StateChanged -= OnPlayerStateChanged;
+
+            Player.StateChanged += OnPlayerStateChanged;
+            _subscribedPlayer = Player;
+        }
+    }
+
+    private void OnPlayerStateChanged() => InvokeAsync(StateHasChanged);
+
+    public void Dispose()
+    {
+        if (_subscribedPlayer != null)
+        {
+            _subscribedPlayer.StateChanged -= OnPlayerStateChanged;
+            _subscribedPlayer = null;
+        }
+    }
 }