The hero screenshot was recaptured by hand, which loses the two settings
that make consecutive captures comparable: the 1600x1000 viewport (the
sample sweep derives its grid columns from the map size, so any other
viewport reflows the whole picture) and hiding the basemap (the gallery
is framed over ocean, but when the OSM tiles do load, coastlines and
place labels sit behind the symbols).

Exposed as `npm run shoot-gallery`, alongside the existing `drive`.