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/Services/AutoDiscoveryService.cs

@@ -17,12 +17,22 @@ public class AutoDiscoveryService : IAutoDiscoveryService
     private const string EnvVarName = "JDESCOPING_CONFIG_PATH";
     private const string AppSettingsFileName = "appsettings.json";
 
+    /// <summary>
+    /// Initializes a new instance of the <see cref="AutoDiscoveryService"/> class.
+    /// </summary>
+    /// <param name="fileSystem">The file system abstraction to use for directory and file checks.</param>
+    /// <param name="logger">Optional logger for recording discovery process information.</param>
     public AutoDiscoveryService(IFileSystem fileSystem, ILogger<AutoDiscoveryService>? logger = null)
     {
         _fileSystem = fileSystem;
         _logger = logger;
     }
 
+    /// <summary>
+    /// Finds the configuration folder using a prioritized search strategy.
+    /// </summary>
+    /// <param name="ct">Cancellation token for the async operation.</param>
+    /// <returns>The path to a valid configuration folder, or null if none is found.</returns>
     public Task<string?> FindConfigFolderAsync(CancellationToken ct = default)
     {
         // 1. Check environment variable