2.1.2

Fixes the whole-app stutter while a long reply streams (#482).

Chat

• Streaming replies render incrementally. The message used to be torn down and re-parsed on every frame, so a long reply pinned the main thread and the entire app stuttered until it finished. Finished blocks now stay in place and only the block being written is re-rendered. On a 6000-word reply, long tasks dropped from 60 to 2 and the stream itself no longer stalls (#503).