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/Probes/AlarmClientWmProbeTests.cs

@@ -135,11 +135,14 @@ public sealed class AlarmClientWmProbeTests : IDisposable
     private IntPtr probeWindow = IntPtr.Zero;
     private string? registeredClass;
 
+    /// <summary>Initializes a new instance of the test class.</summary>
+    /// <param name="output">The test output helper.</param>
     public AlarmClientWmProbeTests(ITestOutputHelper output)
     {
         this.output = output;
     }
 
+    /// <summary>Probes the alarm client for window message behavior (requires AVEVA installed).</summary>
     [Fact(Skip = "Runtime probe — flip Skip=null on the dev rig (AVEVA installed) to capture alarm-path behavior")]
     public void ProbeAlarmClient_OnDevRig_LogsAlarmWindowMessages()
     {
@@ -772,6 +775,7 @@ public sealed class AlarmClientWmProbeTests : IDisposable
         log.Enqueue($"[t={elapsed.Elapsed.TotalSeconds:F3}s] {line}");
     }
 
+    /// <inheritdoc />
     public void Dispose()
     {
         if (wndProcHandle.IsAllocated) wndProcHandle.Free();