Add brightness/contrast sliders, input source switching, and 9-language localization

- Add VCP commands for brightness (10), contrast (12), input source (60)
- Fix UTF-16 encoding for monitor data parsing
- Add system tray app with monitor controls
- Add localization for en, es, fr, de, zh, ja, pt, it, hi
- Update to .NET 9.0
- Add LICENSE and README

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

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

DellMonitorControl/ControlPanel.xaml

@@ -1,14 +1,14 @@
 <UserControl x:Class="DellMonitorControl.ControlPanel"
              xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
-             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
-             xmlns:local="clr-namespace:DellMonitorControl"
-             mc:Ignorable="d">
-    <Grid>
-        <Border  Background="{DynamicResource H3}" CornerRadius="10" MouseLeave="Border_MouseLeave"/>
+             mc:Ignorable="d"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+             Width="280" Height="300">
+    <Grid Background="#333333">
         <StackPanel Name="sp" Margin="10">
-
+            <TextBlock Text="Monitor Control" Foreground="White" FontSize="16" FontWeight="Bold"/>
+            <TextBlock Text="Loading monitors..." Foreground="LightGray" FontSize="12" Margin="0,10,0,0"/>
         </StackPanel>
     </Grid>
 </UserControl>