feat: Implement Playlists and Programs Management

- Added PlaylistsGroupViewModel to manage playlists and selection.
- Introduced ProgramsGroupViewModel for handling program groups and subscriptions.
- Created ProgramsListViewModel to manage individual program listings.
- Developed SettingsViewModel for user settings including playlist management.
- Implemented TVPlayerViewModel as the main view model coordinating screens and data.
- Added PlayerView for video playback with LibVLC integration.
- Created XAML views for PlaylistsGroup, ProgramsGroup, ProgramsList, and Settings.
- Added sample M3U playlist for testing.
- Documented WPF build instructions and project structure in WPF-BUILD.md.
- Configured global.json for .NET SDK versioning.

TV Player Avalonia/Views/PlaylistsGroupView.axaml

@@ -0,0 +1,33 @@
+<UserControl xmlns="https://github.com/avaloniaui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             x:Class="TV_Player.AvaloniaApp.Views.PlaylistsGroupView"
+             x:Name="Root">
+  <ScrollViewer>
+    <ItemsControl ItemsSource="{Binding Programs}">
+      <ItemsControl.ItemsPanel>
+        <ItemsPanelTemplate>
+          <WrapPanel Orientation="Horizontal" />
+        </ItemsPanelTemplate>
+      </ItemsControl.ItemsPanel>
+      <ItemsControl.ItemTemplate>
+        <DataTemplate>
+          <Button Width="260"
+                  Height="120"
+                  Margin="10"
+                  Padding="18"
+                  CornerRadius="16"
+                  Background="#AA111827"
+                  BorderBrush="#EAB308"
+                  BorderThickness="2"
+                  Command="{Binding DataContext.SelectPlaylistCommand, RelativeSource={RelativeSource AncestorType=UserControl}}"
+                  CommandParameter="{Binding}">
+            <StackPanel Spacing="8">
+              <TextBlock Text="{Binding Name}" FontSize="24" FontWeight="Bold" TextWrapping="Wrap" />
+              <TextBlock Text="Open playlist" Foreground="#D1D5DB" />
+            </StackPanel>
+          </Button>
+        </DataTemplate>
+      </ItemsControl.ItemTemplate>
+    </ItemsControl>
+  </ScrollViewer>
+</UserControl>