Rayleigh

Rayleigh scattering coefficient and maximum visual range for a clean Rayleigh atmosphere. The scattering coefficient b_sg scales as λ^-4 (Seinfeld & Pandis 2006, Chapter 15, Problem 15.1A), and the maximum visual range x_v_max = 3.912/b_sg (Eq. 15.36). Both outputs depend only on temperature, pressure, and wavelength — no aerosol loading. Migrated from Aerosol.jl src/mie_scattering.jl `RayleighAtmosphere`.

Optical scattering, absorption, and extinction properties of small particles in the Rayleigh regime (size parameter α = πD_p/λ << 1), from Seinfeld & Pandis (2006) Atmospheric Chemistry and Physics, 2nd ed., Chapter 15, Eqs. 15.4, 15.5, 15.19, 15.21, and 15.41-15.43. Computes the size parameter α, the Clausius-Mossotti factor (m²-1)/(m²+2), and from them the Rayleigh scattering efficiency Q_scat, absorption efficiency Q_abs, extinction efficiency Q_ext, single-scattering albedo ω, and mass efficiencies E_ext/E_scat/E_abs. The two upstream @register_symbolic helper functions (rayleigh_m2_factor_real, rayleigh_m2_factor_imag) are resolved as closed-form algebraic AST, closing the gt-p3ep blocking gap. Migrated from Aerosol.jl src/mie_scattering.jl.