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.Client/Services/RefreshStatusService.cs

@@ -11,11 +11,21 @@ public class RefreshStatusService : IRefreshStatusService
 {
     private readonly HttpClient _httpClient;
 
+    /// <summary>
+    /// Initializes a new instance of the <see cref="RefreshStatusService"/> class.
+    /// </summary>
+    /// <param name="httpClient">The HTTP client for API communication.</param>
     public RefreshStatusService(HttpClient httpClient)
     {
         _httpClient = httpClient;
     }
 
+    /// <summary>
+    /// Gets the data refresh status for a date range.
+    /// </summary>
+    /// <param name="minDt">The minimum date for the status query.</param>
+    /// <param name="maxDt">The maximum date for the status query.</param>
+    /// <returns>A list of data update information for the specified date range.</returns>
     public async Task<List<DataUpdateDto>> GetRefreshStatusAsync(DateTime minDt, DateTime maxDt)
     {
         try