Mythic Masters: bigger horns, claws, eyes and teeth in the beast sheets #3108

Split from #3096 (PR #3105 shipped the glossy materials, weighted normals and dark-hide lift). Still open: the small parts (horns, claws, eyes, teeth) are tiny in the sheets in apps/mythic-masters/beasts/*.json, so the new materials barely show. Enlarge them per sheet, starting with Black Shuck, Cadejo, Mothman, Hidebehind, Kelpie, Minotaur. Judge with bun scripts/beasts.ts --judge.