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.Server/Security/Authentication/AuthSqliteConnectionFactory.cs

@@ -48,6 +48,8 @@ public sealed class AuthSqliteConnectionFactory(IOptions<GatewayOptions> options
     /// non-zero busy timeout so concurrent readers and writers degrade gracefully
     /// rather than surfacing <c>SQLITE_BUSY</c> as a hard failure.
     /// </summary>
+    /// <param name="cancellationToken">Cancellation token for the operation.</param>
+    /// <returns>An opened and configured SQLite connection.</returns>
     public async Task<SqliteConnection> OpenConnectionAsync(CancellationToken cancellationToken)
     {
         SqliteConnection connection = CreateConnection();