docs+ui: backfill XML doc comments and finish dashboard layout pass

Adds missing <summary>/<param> XML docs across 99 server, worker, and test
files so CommentChecker reports zero issues (TreatWarningsAsErrors needs the
analyzer clean). Bundles in WIP dashboard work: NavSection extraction,
MainLayout/site.css/js styling alignment, and DashboardOptions/Auth tweaks.

src/ZB.MOM.WW.MxGateway.Worker.Tests/Ipc/WorkerPipeSessionTests.cs

@@ -1094,12 +1094,16 @@ public sealed class WorkerPipeSessionTests
         }
 
         /// <summary>Records an informational log event.</summary>
+        /// <param name="eventName">The event name.</param>
+        /// <param name="fields">The event fields.</param>
         public void Information(string eventName, IReadOnlyDictionary<string, object?> fields)
         {
             Record(eventName, fields);
         }
 
         /// <summary>Records an error log event.</summary>
+        /// <param name="eventName">The event name.</param>
+        /// <param name="fields">The event fields.</param>
         public void Error(string eventName, IReadOnlyDictionary<string, object?> fields)
         {
             Record(eventName, fields);