🌬️ Wind Turbine Physics (2D): Actuator Disk Streamtube, Betz Limit, Cp-TSR Map and Power Curve

2D companion of the wind turbine sim: actuator-disk streamtube cross-section, Cp(lambda, pitch) map, regulated power curve with cut-in/rated/cut-out, gusty wind trace and numerical checks of the Betz limit and momentum balance.