The traits picker took the whole prompt to detect Ultrathink, so every
keystroke re-rendered it. It now takes the three-state Ultrathink reading
it renders from, and receives the live prompt only when a pick edits it.
The attach button's add-attachments handler closed over the cursor
through the non-stable insert helpers; it now calls their stable forms.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>