An actuator that uses Pigpiox to drive a servo.

Configuration is derived from the joint's motor_profile injected by BB.Actuator.Server:

• Position limits from motor_profile.motor_lower / motor_upper
• Velocity limit from motor_profile.motor_velocity_limit
• PWM range maps linearly to the motor's position range (motor_lower → min_pulse, motor_upper → max_pulse)

When a position command is received, the actuator:

1. Clamps the position to motor limits
2. Converts to PWM pulse width
3. Sends PWM command to pigpiox
4. Publishes a BB.Message.Actuator.BeginMotion via BB.Actuator.publish_begin_motion/3 (which handles the motor → joint-space conversion)

Safety

This actuator implements the BB.Safety behaviour. When the robot is disarmed (either by command or due to supervisor crash), the servo PWM output is disabled by setting the pulse width to 0.