The chat is not a separate assistant. It already has your tree open — ask “why is that bond bent” or “which of these is the allergen” and the answer is about the subject on screen.
Anything with a tree.
No prompt formatting, no naming what you are looking at.
Answers stream in beside the tree; the tree stays where it was.
under the hoodPOST /api/chat/stream, with the current decomposition passed as context.