Mythic Masters: first detail pass, Americas (regions 1-16): faces, hands and feet, markings with today's parts #2817

Part of #2802 (the detail front, now). One worker, from main. Owns only these sheets in apps/wildclash/beasts/ and their built files in public/models/: North America (Pine Barrens to the Ozarks) and Central and South America: jersey-devil, mothman, wampus-cat, hodag, squonk, hidebehind, agropelter, sasquatch, champ, chupacabra, jackalope, rougarou, ozark-howler, ahuizotl, cadejo, mapinguari, boitata, curupira, lobizon, camahueto. The other two blocks are separate issues, so nothing overlaps.

What the builder has today is enough for a lot of the gap the owner sees (3/10, "blob-and-stick"): use it on every sheet in the block before the new parts in #2807 land.

• Faces: eyes placed and sized so they read at fight size (the 6th palette value is glow for the ones that should burn), a brow ridge and a muzzle from nodes with ends: 1, ears from small horn parts with tilt or a two-node chain, an open mouth where the legend bites (a lower-jaw node).
• Hands and feet: short toe or finger chains off each foot and hand node (2-3 nodes each), claws as small horn parts. Keep every foot a rig tip: bun run beasts prints the row, and it must stay ok.
• Markings and colour: paint for legs, muzzles and a darker back, stripes along chains, belly for an underside, blob material for shells and manes. No beast left as one flat colour per region.
• Fur, scales and plates with what exists: tuft rows for a mane, ruff or shaggy back; spikes with low tilt and tight rows read as plates; membrane with feathers for feathered wings.

Rules: art fields only (no stats, moves or code; the builder is #2807). One PR for the block, or two if it grows past ~12 sheets. Judge on ?gallery=0..3 (pages are 16 beasts in roster order), the contact sheets in blender/out/, and a fight per archetype side-on (window.wildclash.camera("side")). Before and after screenshots, scored out of 10, in the PR. A builder gap you hit goes as a comment on #2807, not a workaround in the sheet.