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 WPF/App.xaml.cs

@@ -38,6 +38,8 @@ namespace TV_Player
         protected override void OnExit(ExitEventArgs e)
         {
             _tvPlayer.Dispose();
+            // dispose shared LibVLC instance
+            try { LibVLCManager.Dispose(); } catch { }
             base.OnExit(e);
         }
     }