<h4>Newsfeed Single Post Page Fixes (singlepost.php)</h4><ul><li>Applied all the same fixes from newsfeed_list.php to singlepost.php which had identical bugs: undefined source_url/btnicon/embed, null $pt/$ico guards, getimagesize failure, with_link/embed/image/post_type_id_fk key guards, carousel missing space, $match undefined guard, image_path null guard, global image/iframe error handler.</li></ul>