feat(nav): rewrite top header to zibll 1:1 DOM/CSS/JS contract

Replace hybrid site-nav/drawer shell with zibll navbar-top layouts 1/2/3,
body.mobile-navbar-show drawer, wired NavWalker + aksrt_menu_options meta,
nav_folding/chevron, VIP switches, and SPA/PHP schema parity. No dual-class
compat paths.

functions.php

@@ -136,6 +136,9 @@ if (get_option('aksrt_flushed_version') !== AKSRT_VERSION) {
 \AKSRT\Core\Setup::get_instance()->init();
 \AKSRT\Core\Scripts::get_instance()->init();
 \AKSRT\Admin\Admin::get_instance()->init();
+if (class_exists('\AKSRT\Admin\NavMenuOptions')) {
+    \AKSRT\Admin\NavMenuOptions::init();
+}
 \AKSRT\Auth\OAuth::get_instance()->init();
 if (class_exists('\AKSRT\Auth\WeixinGzh')) {
     \AKSRT\Auth\WeixinGzh::get_instance()->init();