Agent mode is now a side-by-side drawer. The chat docks as a full-height
drawer on the right and the actual space stays visible — and fully
interactive — beside it. The previous full-screen mode rendered a
SpaceMiniView replica of the board while the real one peeked out from
behind the overlay. Outside-click close is disabled while in agent mode so
working on the canvas doesn't dismiss the chat. The mode is toggled by a
labeled switch under the chat input instead of the robot icon in the header.
components/SpaceMiniView.tsx is no longer used.
Fixed
AI scan overlay no longer blocks the canvas. The "scanning your space"
animation is decorative and now lets pointer events through — previously it
covered the board (indefinitely, if the briefing request stalled) and
swallowed clicks.
