Simulation migration notes

PACE's four simulator parameters map directly to native per-world MuJoCo-Warp model fields:

PACE parameter	mjlab / MuJoCo field
Armature	dof_armature
Viscous friction	dof_damping
Static/dynamic friction	dof_frictionloss
Encoder bias	EntityData.encoder_bias
Command delay	PaceDCMotor torque-delay buffer

PACE defines q_encoder = q - bias; mjlab defines q_encoder = q + encoder_bias. The port applies the sign conversion at its boundary, so PACE configuration files and fitted values retain their original meaning.

The upstream fixed-base excitation setting is retained (dt=0.0025 s, decimation=1, base at z=1.0 m).

Unlike mjlab's generic actuator latency, PACE computes and torque-speed-clips the PD command from the current state first, then delays that torque. This is the upstream physical model and is important when a joint moves during a delay.