"Give feedback" button on the info bar above previews

For logged-in users, there should be a "write a comment" button on the info bar above question/exam previews, to add a comment to the editing history tab. Maybe the stamp dropdown should also be there.

Start by locating the question and exam preview info bar and the editing history tab in the editor. Verify how logged-in users currently add comments, then add the requested “write a comment” entry point so the comment appears in editing history; treat the stamp dropdown as an optional follow-up because the issue leaves it undecided.

Written by the indexing model from the issue text.