fix(frontend): close single 1:1 residuals without legacy paths

Unify TOC ownership, real video episode list, slider overlay, single-query related list, Zibll user-card after-box, and new-route subtitle/meta contracts.

inc/helpers/aksrt-single-components.php

@@ -22,7 +22,12 @@ if (!function_exists('aksrt_get_the_subtitle')) :
 		if ($post_id <= 0) {
 			return '';
 		}
-		$subtitle = trim((string) get_post_meta($post_id, '_subtitle', true));
+		// New route: subtitle lives in AKSRT_Post_Meta_Box aggregate meta.
+		$subtitle = '';
+		if (class_exists('AKSRT_Post_Meta_Box')) {
+			$meta = AKSRT_Post_Meta_Box::get_meta($post_id);
+			$subtitle = trim((string) ($meta['subtitle'] ?? ''));
+		}
 		if ($subtitle === '') {
 			return '';
 		}