Class-AB Audio Amplifier V_BE Thermal-Bias Stability & Reactive-Speaker Elliptical SOA Guard

Deterministic Elliptical reactive load trajectory V_ce(t) = V_rail - V_pk*sin(wt), I_c(t) = (V_pk/|Z|)*sin(wt - phi) vs BJT collector-emitter Second-Breakdown curve & thermal loop gain R_e > |dV_be/dT| * R_th * V_rail engine (.json, .sp, .csv) built for Toshiba (2SC5200/2SA1943), onsemi (MJL21194/NJW0281), Cordell / Self Audio, Sanken — zero-upload ephemeral Wasm RAM execution.