fix(nav): never drop top-nav 发布 when submit page URL is empty

aksrt_get_new_post_url() returns '' without a page-submit assignment,
which previously skipped the post action and emptied the multi-type
chip. Fall back to post-new.php, keep a last-resort action list, put
radius/jb paint on the toggle, and force chip visibility CSS.

inc/helpers/aksrt-header-menu-buttons.php

@@ -53,9 +53,11 @@ if (!function_exists('aksrt_get_new_add_actions')) :
 		foreach ($types as $type) {
 			$type = sanitize_key((string) $type);
 			if ($type === 'post') {
-				$url = function_exists('aksrt_get_new_post_url') ? aksrt_get_new_post_url() : admin_url('post-new.php');
+				// Front submit page may be unset → aksrt_get_new_post_url() returns ''.
+				// Never drop the publish chip for that: fall back to WP post-new.
+				$url = function_exists('aksrt_get_new_post_url') ? (string) aksrt_get_new_post_url() : '';
 				if ($url === '') {
-					continue;
+					$url = admin_url('post-new.php');
 				}
 				$out[] = [
 					'type'  => 'post',
@@ -165,7 +167,17 @@ if (!function_exists('aksrt_render_new_add_btns')) :
 	function aksrt_render_new_add_btns(array $types, string $class = '', string $label = ''): string {
 		$actions = aksrt_get_new_add_actions($types);
 		if (!$actions) {
-			return '';
+			// Last resort: keep a write-post entry so the top-nav chip is never blank.
+			$fallback = function_exists('aksrt_get_new_post_url') ? (string) aksrt_get_new_post_url() : '';
+			if ($fallback === '') {
+				$fallback = admin_url('post-new.php');
+			}
+			$actions = [[
+				'type'  => 'post',
+				'url'   => $fallback,
+				'label' => __('写文章', 'aksrt'),
+				'icon'  => 'fas fa-file-alt',
+			]];
 		}
 		if ($label === '') {
 			$label = __('发布', 'aksrt');