Four Kevin-harvested poses (flat/relaxed/fist/grip) as glTF node-local quats
on the canonical Quaternius skeleton. pose_flat shipped to the runtime
HandPoseLayer 2026-08-17 and verified in the dance bed; fist/grip staged,
blocked on the Lena finger-weight repair.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
