S10 model adapted from the Deep Robotics deployment SDK
(`S10_description/s10_mjcf/S10.xml`). Only the 17 mesh files referenced by
`s10.xml` are included. The source XML is BSD-3-Clause, see `../LICENSE_s10`.

Local changes:

- Removed the world floor and light so mjlab can attach the robot to its own
  terrain.
- Removed the torque `<motor>` actuator block; mjlab adds native position
  actuators for the 12 leg joints and native velocity actuators for the 4
  wheels.
- Added names to the four wheel collision cylinders
  (`fl/fr/hl/hr_wheel_collision`) so wheel friction randomisation and contact
  sensors can address them.
- Removed the `<sensor>` block. The SDK XML has unnamed `accelerometer` and
  `gyro` elements, which mjlab tries to wrap as a sensor with an empty name and
  fails with `KeyError: Invalid name ''` during scene initialization. The
  training actor/world model read MuJoCo data directly and do not use these XML
  sensors.
- `robot/config.py` names remaining unnamed collision geoms, clears collision
  margins for Warp MULTICCD compatibility, and delegates solver options to the
  task.
- `meshdir` changed from `../meshes/` to `meshes/`.

Default pose, joint limits, link geometry and inertial values are unchanged
from the SDK model. Actuator gains follow the SDK/IsaacLab S10 configuration:
legs kp=80, kd=2, effort=50 N·m; wheels damping=0.8, effort=14 N·m.
These values are taken from the provided deployment/training projects and are
not independently hardware-calibrated here.