- Add `joint-actuatorforcerange` for clamping total actuator force at joints. Add `sensor-jointactuatorfrc` for sensing total actuator forces on a single joint.
See [documentation](https://mujoco.readthedocs.io/en/latest//modeling.html#actuator-force-clamping) for justification and use cases.
- Add simple car model to `model/`.
- Move actuation-related test models into `engine/testdata/actuation/`.
PiperOrigin-RevId: 549355941
Change-Id: I27f6c1f80426d73a2811ef5ae74684a228b2fbd1
Yuval Tassa