The plate for a picture: its file name, and the size it is captured at.
Here rather than in the capture script, because three places have to agree
about it and only two of them can import a .mjs: scripts/presets/plates.mjs
writes the file, scripts/presets/check.mjs gates that it exists, and
PictureCard requests it over HTTP. Written out in the component instead,
changing the format leaves the check green — it validates the files it named
— while every card in the panel falls through to its "no plate" state, which
is exactly the silent rot the gate exists to make loud.
3:2, because that is the grid the cards are drawn in and a plate cropped by CSS is a composition nobody chose. 480 wide is twice the widest a card is ever drawn at, which covers a 2× display and nothing more — these are committed files and seven of them at 1600 px would be a megabyte of repository for pixels no screen shows.
devtools/src/pictures.ts:37