feat(frontend): align single related/prevnext/maxheight with Zibll

Honor prevnext/authordesc/yiyan settings, multi-tax related queries with
orderby (incl. views), per-post maxheight override, and only expand content
when maxheight is enabled.

inc/classes/class-aksrt-settings.php

@@ -903,7 +903,7 @@ class AKSRT_Settings {
             $related_type = 'category';
         }
         $related_orderby = sanitize_key((string) ($settings['post_related_orderby'] ?? 'rand'));
-        if (!in_array($related_orderby, ['rand', 'relevance', 'date'], true)) {
+        if (!in_array($related_orderby, ['rand', 'relevance', 'date', 'views', 'modified'], true)) {
             $related_orderby = 'rand';
         }