docs: add XML documentation and ConfigManager implementation plans

Add comprehensive XML documentation (param/returns tags) across 132 source
files to improve IntelliSense and API discoverability. Include ConfigManager
design documents and implementation plans for phases 1-9.

NEW/src/Utils/JdeScoping.ConfigManager/Views/MainWindow.axaml.cs

@@ -4,6 +4,9 @@ namespace JdeScoping.ConfigManager.Views;
 
 public partial class MainWindow : Window
 {
+    /// <summary>
+    /// Initializes a new instance of the MainWindow.
+    /// </summary>
     public MainWindow()
     {
         InitializeComponent();