Artifacts open beside the conversation
A page, deck or diagram used to open as a card inside the transcript, inset from every edge — something floating on the conversation rather than the other half of the screen.
It now opens as a proper split: pinned to the right edge, top to bottom, with its own bar carrying the title, the version picker, Source, Download and close. Drag the seam to make it as wide as you need — the width is remembered — or nudge it with the arrow keys. Escape closes it. The sidebar folds to icons while it is up and comes back when you close it.
Each kind of artifact also wears its own icon and colour now — a blue globe for a page, violet for a document, orange for code — so the rail, the transcript and the gallery all tell you what something is before you read its name.
