New maps

src/formats/chk/create.ts builds File ▸ New from nothing, with the same section set a StarEdit map has: IVE2, VCOD and the empty CUWP slots as raw bytes, everything else marked dirty and encoded on save. Terrain is a flat 128×128 Badlands fill laid out the way StarEdit lays it out, in left/right tile pairs sharing one random variation, with ISOM as the two flat quads that alternate across the diamond grid.

Only the Brood War layouts of the revision pairs are written. Blizzard's own Brood War maps carry no UNIS/UPGS/TECS/UPGR/PTEC; a file with both layouts is a hybrid.

requiredSections(fileVersion) is the list Tools ▸ Check Map tests a file against: the common sections, plus the original layouts below revision 205, plus the x layouts from revision 63.