tACS Arnold Tongue: Order-Parameter & Entrainment Map

This is the 2D counterpart to the 3D tACS ring simulator, built from the same coupled cortical-oscillator equations but rendered as two genuinely 2D-native views instead of a flattened 3D scene. The top panel plots every oscillator's phase directly on the unit circle in the complex plane — the population's real mathematical state space — with the Kuramoto order parameter drawn as the vector it literally is. The bottom panel is an independently-computed Arnold-tongue heatmap: a small ensemble is re-simulated to steady state at every combination of stimulation detuning and amplitude, for whatever cortical coupling and dispersion you have dialled in, so you can watch the entrainment region itself grow, shrink and shift live as a function of tissue parameters, with your current stimulation settings marked inside it.