AI seeded comments from robch and then edited by stephentoub (#238)

* AI generated `///` comment updates

* Fix compilation issues

* Fix incorrect XML comment structure

* Update all Client comments

* Update all Configuration comments

* Update all Messages comments

* Update all Transport comments

* Update all Types comments

* Update all Server comments

* Undo some commenting

---------

Co-authored-by: Stephen Toub <stoub@microsoft.com>

src/ModelContextProtocol/ProgressNotificationValue.cs

@@ -1,9 +1,21 @@
-namespace ModelContextProtocol;
+namespace ModelContextProtocol;
 
 /// <summary>Provides a progress value that can be sent using <see cref="IProgress{ProgressNotificationValue}"/>.</summary>
 public record struct ProgressNotificationValue
 {
-    /// <summary>Gets or sets the progress thus far.</summary>
+    /// <summary>
+    /// Gets or sets the progress thus far.
+    /// </summary>
+    /// <remarks>
+    /// <para>
+    /// This value typically represents either a percentage (0-100) or the number of items processed so far (when used with the <see cref="Total"/> property).
+    /// </para>
+    /// <para>
+    /// When reporting progress, this value should increase monotonically as the operation proceeds.
+    /// Values are typically between 0 and 100 when representing percentages, or can be any positive number
+    /// when representing completed items in combination with the <see cref="Total"/> property.
+    /// </para>
+    /// </remarks>
     public required float Progress { get; init; }
 
     /// <summary>Gets or sets the total number of items to process (or total progress required), if known.</summary>