Looks very promising! Nice work. I ran into a few bugs using the not-signed in version.

User test: https://www.loom.com/share/725b786ee7b14b589c2fb9a4c5afd5e6?...

Thanks for finding the bug! I've fixed it, but I think I should provide another alternative for adding elements to the editor—like using CMD+K with a dialog or a plus sign icon for mobile UX.

Looks good! Same issue as shown in Loom below. Without signup and create form. Shortcodes don't immediately show up. After deleting and trying many times, it starts working. So on page load, there is no shortcodes