VDP–3D — dx/dt=y, dy/dt=−x+μ(1−x²)y+ε z, dz/dt=−γ z+x y. Classic μ=0.5 ε=0.2 γ=0.5. Distinct from forced-vdp / rayleigh. RK4. Gold trail, cap 650. RM = settled silhouette, no animate-on.