Phone editor with bottom-sheet editing, structured prompt output, and a new logo

- Prompt: headed sections with the full color scheme, per-part style notes
  for the parts in use, and general guidance; no loading/progress text
  unless those parts are placed
- Phone: one fixed screen, buttons only, select tool only, tap empty space
  to deselect, plus button adds a button, edit/duplicate/delete bar and a
  compact bottom sheet, theme and language in a settings sheet, zoomed to
  the screen width on start
- Logo: a frozen frame of the loading indicator with the layers mark inside
- Desktop: fit button next to the zoom control

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>