Add a self-contained rt/smpl publisher in the pico_headset teleoperator
(pico_publisher.py + numpy SMPL FK in smpl_fk.py + vendored skeleton table)
so headset whole-body teleop no longer depends on gear_sonic/torch; only
xrobotoolkit_sdk is needed at the headset.
Also: share lowstate_to_obs/get_gravity_orientation via g1_utils (dedup
sonic_pipeline and UnitreeG1.get_observation), and fix dataset-replay joint
ordering (Unitree -> IsaacLab) for sonic.py --replay-dataset.
Co-authored-by: Cursor <cursoragent@cursor.com>
Martino Russi