Version-to-HEAD Mode Transition/Navigation

[jamlung-ri]

In v3, we need to make sure it's clear when an editing user is moving from a view-only saved version to the edit-ready HEAD version. How is a user entering the mode where they can make edits to a source or collection? How do we make it clear that the published version they're looking at is not editable and that they have to go to HEAD mode to edit?

The first step to make here is a table of scenarios, which includes different types of content, who the person is that's viewing it, and how the content should appear to them.