feat(nav): complete remaining zibll parity (search, i18n, senior menus, CSS)

- Remove obsolete dual-path nav CSS; add utilities + language dropdown styles
- Wire header/mobile translate switcher from i18n config
- Layout-2 inline search hot keywords panel; nav_folding on resize
- NavMenuOptions JSON editors for graphic_card / multi_column_links
- Section-navs zibll posts-nav-lists; page-navs enqueue; mobile article TOC box
- SPA/PHP user-card publish type; rebuild admin assets

inc/helpers/aksrt-i18n-switch.php

@@ -147,3 +147,56 @@ function aksrt_render_language_switcher(string $style = 'dropdown'): string {
 
     return $html;
 }
+
+/**
+ * Header language dropdown (zibll zib_get_translate_language_btn).
+ * Uses SPA i18n_available_langs when i18n enabled and position includes header.
+ *
+ * @param string $class Extra classes.
+ */
+function aksrt_get_translate_language_btn(string $class = ''): string {
+	if (!class_exists('\AKSRT\Settings\Settings')) {
+		return '';
+	}
+	$cfg = \AKSRT\Settings\Settings::get_i18n_config();
+	if (empty($cfg['enabled'])) {
+		return '';
+	}
+	$pos = (string) ($cfg['switcherPosition'] ?? 'footer');
+	if (!in_array($pos, ['header', 'both'], true)) {
+		return '';
+	}
+
+	$raw = (string) ($cfg['availableLangs'] ?? '');
+	$buttons = [];
+	foreach (preg_split('/
+|␍|
+/', $raw) as $line) {
+		$line = trim($line);
+		if ($line === '' || strpos($line, '|') === false) {
+			continue;
+		}
+		[$code, $label] = array_map('trim', explode('|', $line, 2));
+		if ($code === '' || $label === '') {
+			continue;
+		}
+		$buttons[] = ['language' => $code, 'text' => $label];
+	}
+	if (!$buttons) {
+		return '';
+	}
+
+	$buttons_html = '';
+	foreach ($buttons as $button) {
+		$buttons_html .= '<li><a href="javascript:;" class="translate-button translate-ignore flex ac" data-language="'
+			. esc_attr($button['language']) . '">' . esc_html($button['text']) . '</a></li>';
+	}
+	$is_mobile = wp_is_mobile();
+	$dropdown  = '<ul class="dropdown-menu hover-show-con">' . $buttons_html . '</ul>';
+	$hover     = !$is_mobile ? ' hover-show' : '';
+	$toggle    = !$is_mobile ? '' : ' data-toggle="dropdown"';
+	return '<div class="dropdown language-dropdown ' . esc_attr($class) . $hover . '">'
+		. '<a href="javascript:;" class="toggle-radius"' . $toggle . ' title="' . esc_attr__('切换语言', 'aksrt') . '">'
+		. '<i class="fas fa-language" aria-hidden="true"></i></a>' . $dropdown . '</div>';
+}
+