The RomM export fetched known_bios_files.json and never read it: the
fixture was rebuilt in our own order, so three corrections came out
as a diff of the whole file and a key we had not transcribed was
deleted. The export now starts from RomM's file, keeps its order and
fields, and only changes the values it corrects.
A truth that accepts several sizes left an export with no size even
where the platform states one of them for the same dump, and RomM's
fixture then received the string None, which RomM cannot parse. A
size list now admits the platform's own size, RomM keeps its value
when nothing settles one, and validation requires a number.
Abdessamad Derraz