Two-state flow with go-live dialog, unmissable live indicators, taskbar overlay

MainWindow.xaml.cs

@@ -1,11 +1,32 @@
-using System.Windows;
+using System.ComponentModel;
+using System.Windows;
+using System.Windows.Media;
+using ytLive.ViewModels;
 
 namespace ytLive;
 
 public partial class MainWindow : Window
 {
+    private readonly MainViewModel _viewModel;
+
     public MainWindow()
     {
         InitializeComponent();
+        _viewModel = (MainViewModel)DataContext;
+        _viewModel.PropertyChanged += OnViewModelPropertyChanged;
+        UpdateTaskbarOverlay();
+    }
+
+    private void OnViewModelPropertyChanged(object? sender, PropertyChangedEventArgs e)
+    {
+        if (e.PropertyName == nameof(MainViewModel.IsLive))
+            UpdateTaskbarOverlay();
+    }
+
+    private void UpdateTaskbarOverlay()
+    {
+        TaskbarInfo.Overlay = _viewModel.IsLive
+            ? (ImageSource)FindResource("LiveOverlay")
+            : null;
     }
 }