It seems like Threads posts are no longer /t/post_id, but now @whoever/post/post_id (such as https://www.threads.net/@pijusmusic/post/DESGn_BsdiQ).

As such, we should recognize these links, and probably still clean up to the /t/post_id format (which still works and is probably more persistent since it doesn't depend on the profile name not changing).