regular-shock-reflectionlisted

# Regular Shock Reflection (aerodynamics/high-speed/regular-shock-reflection) When an oblique shock from a wedge impinges on a wall or symmetry plane in supersonic flow, the wall turns the flow back parallel to itself and a second oblique shock, the reflected shock, leaves the impingement point. This leaf computes the classical two-shock REGULAR reflection: it solves the theta-beta-M relation for the incident weak shock at the upstream Mach number M1 and deflection angle theta, marches the full state behind the incident shock, solves theta-beta-M again on that downstream state for the reflected shock that turns the flow back by the same deflection, and multiplies the two sets of oblique-shock ratios into the post-reflection state. It judges the interaction regular when the required reflected deflection stays below the reflected-shock detachment limit at the intermediate Mach number M2, and Mach (irregular) otherwise, as the detachment-criterion flag. It pairs with aerodynamics/high-speed/ oblique-shock for the single-shock weak and strong branch relations it reuses, with aerodynamics/high-speed/normal-shock for the normal-shock total-pressure formula evaluated at Mn1, and with aerodynamics/high-speed/ shock-expansion-airfoil where every surface shock is itself an oblique-shock solve of this kind. Mach-reflection flowfield details (triple point, Mach stem, slip line) are not modeled, and the von Neumann transition criterion is not implemented. Deterministic, pure stdlib. ##