Refactor PLib video library manager to use ReactiveUI, replacing CommunityToolkit.Mvvm. Update dependencies, enhance thumbnail caching logic, and improve UI responsiveness with reactive commands. Remove obsolete PLib.slnx file and update README.md to reflect changes.

src/PLib.Desktop/Views/MainWindow.axaml

@@ -224,7 +224,7 @@
 
         <Button Grid.Column="2"
                 Content="Отмена"
-                Command="{Binding ScanCancelCommand}"
+                Command="{Binding CancelScanCommand}"
                 IsVisible="{Binding IsScanning}" />
 
       </Grid>

src/PLib.Desktop/Views/MainWindow.axaml.cs

@@ -1,8 +1,9 @@
-using Avalonia.Controls;
+using ReactiveUI.Avalonia;
+using PLib.Desktop.ViewModels;
 
 namespace PLib.Desktop.Views;
 
-public sealed partial class MainWindow : Window
+public sealed partial class MainWindow : ReactiveWindow<MainWindowViewModel>
 {
     public MainWindow() => InitializeComponent();
 }