Apply the same tilt to every stacked part and rotate it about its local
Y axis instead of Z. Default tilt to 1 degree when a stacking strategy
is present, and arc the poker deck along the surface's bottom edge.
Replace the per-part lift with a local Y-axis tilt that fans the stack,
and add zStart/zEnd to ramp the stack's height across the curve so it
arches in 3D. Update the poker deck and docs accordingly.