[FEATURE] Consider friction in primary pulley as a function of coupling torque

[gr812b]

Feature Description
Technically, primary is "torque reactive" not dissimilar to secondary, however acting in the axial shift direction. Since the two sheaves interact via rollers with a static coefficient of friction (rolling), the torque between the two applies a normal force.

This provides dynamic damping into the shift equation, however also much complexity. Make sure to include derivation in relevant documentation.