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/DashboardLdapLiveTests.cs

@@ -10,6 +10,7 @@ namespace ZB.MOM.WW.MxGateway.IntegrationTests;
 [Trait("Category", "LiveLdap")]
 public sealed class DashboardLdapLiveTests
 {
+    /// <summary>Verifies that an admin user in the GwAdmin group authenticates successfully.</summary>
     [LiveLdapFact]
     public async Task AuthenticateAsync_AdminInGwAdminGroup_Succeeds()
     {
@@ -38,6 +39,7 @@ public sealed class DashboardLdapLiveTests
             && claim.Value == DashboardRoles.Admin);
     }
 
+    /// <summary>Verifies that a readonly user without GwAdmin group fails to authenticate.</summary>
     [LiveLdapFact]
     public async Task AuthenticateAsync_ReadOnlyUserMissingGwAdminGroup_Fails()
     {
@@ -53,6 +55,7 @@ public sealed class DashboardLdapLiveTests
         Assert.DoesNotContain("readonly123", result.FailureMessage, StringComparison.Ordinal);
     }
 
+    /// <summary>Verifies that authentication with wrong password fails without leaking the password.</summary>
     [LiveLdapFact]
     public async Task AuthenticateAsync_AdminWithWrongPassword_FailsWithoutLeakingPassword()
     {
@@ -71,6 +74,7 @@ public sealed class DashboardLdapLiveTests
         Assert.DoesNotContain(wrongPassword, result.FailureMessage, StringComparison.Ordinal);
     }
 
+    /// <summary>Verifies that authentication with unknown username fails.</summary>
     [LiveLdapFact]
     public async Task AuthenticateAsync_UnknownUsername_Fails()
     {
@@ -87,6 +91,7 @@ public sealed class DashboardLdapLiveTests
         Assert.Null(result.Principal);
     }
 
+    /// <summary>Verifies that authentication fails gracefully when the server is unreachable.</summary>
     [LiveLdapFact]
     public async Task AuthenticateAsync_ServerUnreachable_FailsWithoutThrowing()
     {