Add About dialog with version info

- About button added next to Exit in header
- Shows app name, version, author, and company
- Version 1.1.4

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

DellMonitorControl/MainWindow.xaml.cs

@@ -70,6 +70,85 @@ public partial class MainWindow : Window
         Application.Current.Shutdown();
     }
 
+    private void AboutButton_Click(object sender, RoutedEventArgs e)
+    {
+        var version = System.Reflection.Assembly.GetExecutingAssembly().GetName().Version;
+        var versionStr = $"{version?.Major}.{version?.Minor}.{version?.Build}";
+
+        var aboutWindow = new Window
+        {
+            Title = "About Monitor Control",
+            Width = 300,
+            Height = 180,
+            WindowStartupLocation = WindowStartupLocation.CenterScreen,
+            ResizeMode = ResizeMode.NoResize,
+            WindowStyle = WindowStyle.None,
+            AllowsTransparency = true,
+            Background = Brushes.Transparent
+        };
+
+        var border = new Border
+        {
+            Background = new SolidColorBrush(Color.FromArgb(0xF0, 0x33, 0x33, 0x33)),
+            CornerRadius = new CornerRadius(8),
+            BorderBrush = new SolidColorBrush(Color.FromRgb(0x55, 0x55, 0x55)),
+            BorderThickness = new Thickness(1),
+            Padding = new Thickness(20)
+        };
+
+        var stack = new StackPanel { VerticalAlignment = VerticalAlignment.Center };
+
+        stack.Children.Add(new TextBlock
+        {
+            Text = "Monitor Control",
+            Foreground = Brushes.White,
+            FontSize = 18,
+            FontWeight = FontWeights.SemiBold,
+            HorizontalAlignment = HorizontalAlignment.Center,
+            Margin = new Thickness(0, 0, 0, 5)
+        });
+
+        stack.Children.Add(new TextBlock
+        {
+            Text = $"Version {versionStr}",
+            Foreground = Brushes.LightGray,
+            FontSize = 12,
+            HorizontalAlignment = HorizontalAlignment.Center,
+            Margin = new Thickness(0, 0, 0, 10)
+        });
+
+        stack.Children.Add(new TextBlock
+        {
+            Text = "by David H. Friedel Jr",
+            Foreground = Brushes.Gray,
+            FontSize = 11,
+            HorizontalAlignment = HorizontalAlignment.Center
+        });
+
+        stack.Children.Add(new TextBlock
+        {
+            Text = "MarketAlly",
+            Foreground = Brushes.Gray,
+            FontSize = 11,
+            HorizontalAlignment = HorizontalAlignment.Center,
+            Margin = new Thickness(0, 0, 0, 15)
+        });
+
+        var closeBtn = new Button
+        {
+            Content = "OK",
+            Width = 80,
+            HorizontalAlignment = HorizontalAlignment.Center,
+            Style = (Style)FindResource("DarkButton")
+        };
+        closeBtn.Click += (s, args) => aboutWindow.Close();
+        stack.Children.Add(closeBtn);
+
+        border.Child = stack;
+        aboutWindow.Content = border;
+        aboutWindow.ShowDialog();
+    }
+
     private void ShowLogButton_Click(object sender, RoutedEventArgs e)
     {
         var logWindow = new Window