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/JdeScoping.Core/ViewModels/OperatorViewModel.cs

@@ -5,10 +5,22 @@ namespace JdeScoping.Core.ViewModels;
 /// </summary>
 public class OperatorViewModel
 {
+    /// <summary>
+    /// Gets or sets the operator's address number.
+    /// </summary>
     public long AddressNumber { get; set; }
+
+    /// <summary>
+    /// Gets or sets the operator's user ID.
+    /// </summary>
     public string UserId { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Gets or sets the operator's full name.
+    /// </summary>
     public string FullName { get; set; } = string.Empty;
 
+    /// <inheritdoc />
     public override bool Equals(object? obj)
     {
         if (obj is OperatorViewModel other)
@@ -18,5 +30,6 @@ public class OperatorViewModel
         return false;
     }
 
+    /// <inheritdoc />
     public override int GetHashCode() => UserId.GetHashCode();
 }