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/DellMonitorControl.csproj

@@ -15,9 +15,9 @@
 	</PropertyGroup>
 
 	<PropertyGroup>
-		<Version>1.1.3</Version>
-		<AssemblyVersion>1.1.3.0</AssemblyVersion>
-		<FileVersion>1.1.3.0</FileVersion>
+		<Version>1.1.4</Version>
+		<AssemblyVersion>1.1.4.0</AssemblyVersion>
+		<FileVersion>1.1.4.0</FileVersion>
 	</PropertyGroup>
 
 	<ItemGroup>