The resize to 192px isn't worthwhile now that sprites are only downloaded
when viewed or saved on request, and then kept forever. Restore the
original files and the script's no-resize default, drop the detail view
size cap, and regenerate the sprite manifest with the original sizes.
Sprites were shipped at 512x512 but render at 44-64px in the box grid.
Resizing to 192px halves each file (median 15.5KB -> 7.6KB); a full dex
of artwork drops from 16.6MB to 7.6MB.
The sprite build now also writes static/sprites-small/manifest.json,
listing every sprite (all forms, shiny and female variants) with its
size, so the offline worker can save the complete set and report what
is missing. A unit test keeps it in step with the files on disk.
Josh Creek