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/Models/Infrastructure/DataUpdateDto.cs

@@ -6,20 +6,34 @@ namespace JdeScoping.Core.Models.Infrastructure;
 /// </summary>
 public class DataUpdateDto
 {
+    /// <summary>The start time of the data update.</summary>
     public DateTime StartDt { get; set; }
+    /// <summary>The end time of the data update.</summary>
     public DateTime? EndDt { get; set; }
 
+    /// <summary>The number of branch records updated.</summary>
     public int BranchRecords { get; set; }
+    /// <summary>The number of profit center records updated.</summary>
     public int ProfitCenterRecords { get; set; }
+    /// <summary>The number of work center records updated.</summary>
     public int WorkCenterRecords { get; set; }
+    /// <summary>The number of organizational hierarchy records updated.</summary>
     public int OrgHierarchyRecords { get; set; }
+    /// <summary>The number of status code records updated.</summary>
     public int StatusCodeRecords { get; set; }
+    /// <summary>The number of user records updated.</summary>
     public int UserRecords { get; set; }
+    /// <summary>The number of item records updated.</summary>
     public int ItemRecords { get; set; }
+    /// <summary>The number of lot records updated.</summary>
     public int LotRecords { get; set; }
+    /// <summary>The number of work order records updated.</summary>
     public int WorkOrderRecords { get; set; }
+    /// <summary>The number of work order step records updated.</summary>
     public int WorkOrderStepRecords { get; set; }
+    /// <summary>The number of work order component records updated.</summary>
     public int WorkOrderComponentRecords { get; set; }
 
+    /// <summary>Whether the data update was successful.</summary>
     public bool WasSuccessful { get; set; }
 }