Rayleigh — dx/dt=y, dy/dt=−x+μ·y(1−y²/3), dz/dt=c(x−z). Classic μ=2 c=0.15. Dual μ+c sliders. Display embed (x,y,z). Distinct from van-der-pol.html, duffing.html, rayleigh-benard.html, coullet.html. Bulk centroid ≈ (0.0034, 0.0008, 0.0000). RK4 mechanical fold. Gold low-alpha trail, cap 650. RM = settled silhouette, no animate-on.