The streaming hook handles the step, result, followUps and clarification
frames and sends followUp and clarification on the tool route only. The
bubble gains slots for the step list, the tables and the method line; the
thread offers chips under the latest assistant turn only; the conversation
shows the clarification card above the composer and marks a typed answer
as answering it. The tables of a persisted message load lazily when it
scrolls into view, seeded from the stream for the turn that produced them.
The new components render nothing yet.