The UI Extensions SDK documentation mentions that it’s possible to build content management extensions, which “reside on the sidebar and allow for actions that include every element in the entry.”
Unfortunately, I can’t find any documentation as to how one goes about building these content management extensions that aren’t tied to a particular field. The Netlify build sample sidebar extension is a great starting point, but it merely instructs you to “Setup sidebar extension” as step 1.
Specifically, when you’re creating an extension via the extension management UI, you must select a field type, which doesn’t seem to apply to sidebar extensions.
Thanks for the help!