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.IntegrationTests/LiveLdapFactAttribute.cs

@@ -4,6 +4,7 @@ public sealed class LiveLdapFactAttribute : FactAttribute
 {
     public const string EnableVariableName = "MXGATEWAY_RUN_LIVE_LDAP_TESTS";
 
+    /// <summary>Initializes a live LDAP test fact that skips if LDAP tests are not enabled.</summary>
     public LiveLdapFactAttribute()
     {
         if (!Enabled)
@@ -12,5 +13,6 @@ public sealed class LiveLdapFactAttribute : FactAttribute
         }
     }
 
+    /// <summary>Gets a value indicating whether live LDAP tests are enabled.</summary>
     public static bool Enabled => IntegrationTestEnvironment.IsEnabled(EnableVariableName);
 }