Each finger's intermediate joint and the thumb's intermediate and distal joints follow their motor joint as in the URDF's <mimic>, so the model moves its fingers without the URDF. robotusd.from_urdf now writes PhysxMimicJointAPI for <mimic> joints; nothing else in the USD changed.
Add Unitree G1 with Dex1-1 grippers (g1_body29_dex1)
