Add an image button to the comment toolbar backed by a new upload route
(images only, 5 MB, stored under comments/<userId>/), inserted as Markdown.
Only images served from our own storage are rendered: a third-party src would
be fetched by every reader of the lesson, exposing their address. Such links
are shown as plain links instead — this also defuses the external images a few
existing comments already carry.
admins
005cd329b2