Improve LibVLC stability and add external playback host

- Add LibVLCManager singleton for safer LibVLC lifetime management
- Introduce VlcHostClient and VlcHost.exe for external playback via JSON commands
- Enhance VideoPlayer with error recovery and dependency property for SourceUrl
- Implement IDisposable in ProgramsData and ViewModels for better cleanup
- Update NuGet packages: LibVLCSharp to 3.9.6, System.Reactive to 6.1.0
- Add robust error handling and resource disposal throughout
- Improve program guide handling in PlayerViewModel

TV Player Avalonia/ViewModels/TVPlayerViewModel.cs

@@ -155,5 +155,18 @@ public class TVPlayerViewModel : IDisposable
     {
         if (_mainWindowViewModel.CurrentViewModel is IDisposable disposable)
             disposable.Dispose();
+
+        if (PlayListsData != null)
+        {
+            foreach (var kv in PlayListsData)
+            {
+                try { kv.Value.Dispose(); } catch { }
+            }
+            PlayListsData.Clear();
+        }
+        if (CurrentProgramsData != null)
+        {
+            try { CurrentProgramsData.Dispose(); } catch { }
+        }
     }
 }