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.Tests/Gateway/Grpc/EventStreamServiceTests.cs

@@ -355,8 +355,12 @@ public sealed class EventStreamServiceTests
 
     private sealed class ThrowingDashboardEventBroadcaster : ZB.MOM.WW.MxGateway.Server.Dashboard.Hubs.IDashboardEventBroadcaster
     {
+        /// <summary>Gets the count of publish attempts.</summary>
         public int PublishAttempts { get; private set; }
 
+        /// <summary>Increments the attempt count and throws a simulated failure.</summary>
+        /// <param name="sessionId">The session identifier.</param>
+        /// <param name="mxEvent">The event to publish.</param>
         public void Publish(string sessionId, MxEvent mxEvent)
         {
             PublishAttempts++;