sync: refresh ATTRIBUTION (#838)

sync: vertical descent + spine guard + curation (#838), 46 clips

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Update card for v4 architecture + corrected 6D

v4 vocab (frame=world, fps=30, 13 actions)

v4 corrected-6D model — column-packed rotations, world-frame, 30fps (#411)

Experimental from-scratch text-to-motion model (#411): CMU+Quaternius CC0, ONNX

initial commit