Lay a screen out again when its size changes, and settle the desktop frame

A frame switched between phone and desktop now carries its parts across:
edge-to-edge bars take the new width, parts sized to the old content width
take the new one, a card or an image keeps its shape, anything that fell
outside is pulled back in, and the screen is laid out again by the tidy
rules. Screens to the right move over so nothing overlaps, and the view
stays put. Size and position changes ease over the settle time.

Every screen keeps the dark bezel; the desktop only has flatter corners.
The frame label holds the phone / desktop switch in place of the icon and
keeps a readable size across zoom levels.

The prompt's target follows the screens: web once a desktop screen exists,
Android otherwise, unless the author picked one. The target line, the
screen headings and the per-screen sizes are written per viewport in
Japanese, English and Chinese, and a single-screen prompt describes only
that screen. An explicit Android target treats desktop screens as a
landscape tablet.

The preview cross-fades between screens of different sizes, eases its shell
to the size of the screen on show, and scales to the largest screen so a
swipe never rescales it. Opening the preview glides the camera to the
screen first; closing it glides back.

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