TASK 20 step 2: hotkey config UI + modifier chord persistence + conflict detection

HotkeyConfigDialog.xaml.cs

@@ -0,0 +1,69 @@
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Input;
+using ytLive.Services;
+using ytLive.ViewModels;
+
+namespace ytLive;
+
+public partial class HotkeyConfigDialog : Window
+{
+    private readonly HotkeyConfigViewModel _viewModel;
+
+    public HotkeyConfigDialog(HotkeyConfigViewModel viewModel)
+    {
+        InitializeComponent();
+        DataContext = viewModel;
+        _viewModel = viewModel;
+        viewModel.SaveRequested += () => DialogResult = true;
+        viewModel.CancelRequested += () => DialogResult = false;
+    }
+
+    private void ChordButton_Click(object sender, RoutedEventArgs e)
+    {
+        if (sender is not FrameworkElement { Tag: HotkeyBindingRow row }) return;
+
+        _viewModel.StartCaptureCommand.Execute(row);
+
+        // Enter capture mode: listen for the next key combo on this specific button.
+        if (row.IsCapturing && sender is Button button)
+        {
+            button.PreviewKeyDown += ChordButton_PreviewKeyDown;
+            button.Focus();
+        }
+    }
+
+    private void ChordButton_PreviewKeyDown(object sender, KeyEventArgs e)
+    {
+        if (sender is not Button button) return;
+        button.PreviewKeyDown -= ChordButton_PreviewKeyDown;
+
+        e.Handled = true;
+
+        // Escape cancels capture without changing the binding.
+        if (e.Key == Key.Escape)
+        {
+            _viewModel.CancelCapture();
+            return;
+        }
+
+        // Skip bare modifier-only presses — wait for a real key.
+        var key = e.Key == Key.System ? e.SystemKey : e.Key;
+        if (key is Key.LeftCtrl or Key.RightCtrl or Key.LeftAlt or Key.RightAlt
+                or Key.LeftShift or Key.RightShift or Key.LWin or Key.RWin)
+        {
+            // Re-enter capture — the button is still focused, re-subscribe.
+            button.PreviewKeyDown += ChordButton_PreviewKeyDown;
+            return;
+        }
+
+        var chord = HotkeyChord.FromWpf(key, Keyboard.Modifiers);
+        _viewModel.AssignCapturedChord(chord);
+    }
+
+    private void UnbindButton_Click(object sender, RoutedEventArgs e)
+    {
+        if (sender is FrameworkElement { Tag: HotkeyBindingRow row })
+            _viewModel.UnbindCommand.Execute(row);
+    }
+}