Fix issue 925 (wheel rotation calculation)

[tomo0613]

#925

explanation (by Claude):

The Bug
In src/control/ray_cast_vehicle_controller.rs, the wheel rotation update uses a fwd (forward) vector computed independently from the chassis rotation:

let mut fwd = chassis.position().rotation * Vector::ith(self.index_forward_axis, 1.0);
let proj = fwd.dot(wheel.raycast_info.contact_normal_ws);
fwd -= wheel.raycast_info.contact_normal_ws * proj;

But the friction impulse system in update_friction() computes forward as:

self.forward_ws[i] = surf_normal_ws.cross(self.axle[i]).normalize_or_zero();

These two methods produce vectors that can point in opposite directions depending on the axle axis convention. For example, with index_forward_axis = 2 (Z forward) and a wheel axle along -X:

• forward_ws[i] = Y × (-X) = -Z
• fwd = +Z ← exact opposite!

The result: delta_rotation has the wrong sign, making the wheel appear to spin backward (and it cancels out to ~0). When steering is applied, the axle rotates, which partially corrupts/corrects the mismatch — which is exactly why rotation only appears when steering.