Nonresonant CR-current instability — mode solver & field animation

Solves h₁(ω)=0 (electrostatic) and h₂(ω)² = h₃(ω)² (transverse, R/L) from Gupta, Caprioli & Haggerty Eqs. (A9)–(A11), then animates the resulting perturbed electron/ion velocities and E₁, B₁, J₁ fields along x̂.

x   y   z
drag = orbit · scroll = zoom · right-drag = pan