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/Sessions/GatewaySessionTests.cs

@@ -187,35 +187,46 @@ public sealed class GatewaySessionTests
         private readonly TaskCompletionSource _shutdownStarted = new(TaskCreationOptions.RunContinuationsAsynchronously);
         private readonly TaskCompletionSource _shutdownReleased = new(TaskCreationOptions.RunContinuationsAsynchronously);
 
+        /// <summary>Gets the session identifier.</summary>
         public string SessionId { get; } = "session-test";
 
+        /// <summary>Gets the worker process identifier.</summary>
         public int? ProcessId { get; } = 1234;
 
+        /// <summary>Gets or sets the worker client state.</summary>
         public WorkerClientState State { get; private set; } = WorkerClientState.Ready;
 
+        /// <summary>Gets the last recorded heartbeat timestamp.</summary>
         public DateTimeOffset LastHeartbeatAt { get; } = DateTimeOffset.UtcNow;
 
+        /// <summary>Gets the count of shutdown invocations.</summary>
         public int ShutdownCount { get; private set; }
 
+        /// <summary>Gets the count of dispose invocations.</summary>
         public int DisposeCount { get; private set; }
 
+        /// <summary>Waits for shutdown to start.</summary>
         public Task WaitForShutdownStartAsync()
         {
             return _shutdownStarted.Task.WaitAsync(TimeSpan.FromSeconds(5));
         }
 
+        /// <summary>Releases the shutdown block.</summary>
         public void ReleaseShutdown()
         {
             _shutdownReleased.TrySetResult();
         }
 
+        /// <inheritdoc />
         public Task StartAsync(CancellationToken cancellationToken) => Task.CompletedTask;
 
+        /// <inheritdoc />
         public Task<WorkerCommandReply> InvokeAsync(
             WorkerCommand command,
             TimeSpan timeout,
             CancellationToken cancellationToken) => Task.FromResult(new WorkerCommandReply());
 
+        /// <inheritdoc />
         public async IAsyncEnumerable<WorkerEvent> ReadEventsAsync(
             [EnumeratorCancellation] CancellationToken cancellationToken)
         {
@@ -223,6 +234,7 @@ public sealed class GatewaySessionTests
             yield break;
         }
 
+        /// <inheritdoc />
         public async Task ShutdownAsync(TimeSpan timeout, CancellationToken cancellationToken)
         {
             ShutdownCount++;
@@ -231,11 +243,13 @@ public sealed class GatewaySessionTests
             State = WorkerClientState.Closed;
         }
 
+        /// <inheritdoc />
         public void Kill(string reason)
         {
             State = WorkerClientState.Faulted;
         }
 
+        /// <inheritdoc />
         public ValueTask DisposeAsync()
         {
             DisposeCount++;
@@ -245,23 +259,31 @@ public sealed class GatewaySessionTests
 
     private sealed class FakeWorkerClient : IWorkerClient
     {
+        /// <summary>Gets the session identifier.</summary>
         public string SessionId { get; } = "session-test";
 
+        /// <summary>Gets the worker process identifier.</summary>
         public int? ProcessId { get; } = 1234;
 
+        /// <summary>Gets the worker client state.</summary>
         public WorkerClientState State { get; } = WorkerClientState.Ready;
 
+        /// <summary>Gets the last recorded heartbeat timestamp.</summary>
         public DateTimeOffset LastHeartbeatAt { get; } = DateTimeOffset.UtcNow;
 
+        /// <summary>Gets the count of dispose invocations.</summary>
         public int DisposeCount { get; private set; }
 
+        /// <inheritdoc />
         public Task StartAsync(CancellationToken cancellationToken) => Task.CompletedTask;
 
+        /// <inheritdoc />
         public Task<WorkerCommandReply> InvokeAsync(
             WorkerCommand command,
             TimeSpan timeout,
             CancellationToken cancellationToken) => Task.FromResult(new WorkerCommandReply());
 
+        /// <inheritdoc />
         public async IAsyncEnumerable<WorkerEvent> ReadEventsAsync(
             [EnumeratorCancellation] CancellationToken cancellationToken)
         {
@@ -269,12 +291,15 @@ public sealed class GatewaySessionTests
             yield break;
         }
 
+        /// <inheritdoc />
         public Task ShutdownAsync(TimeSpan timeout, CancellationToken cancellationToken) => Task.CompletedTask;
 
+        /// <inheritdoc />
         public void Kill(string reason)
         {
         }
 
+        /// <inheritdoc />
         public ValueTask DisposeAsync()
         {
             DisposeCount++;