Simtop

Surface runoff and infiltration for the pervious-road urban surface, following Oleson et al. (2010, CLM Tech Note Ch. 5) §5.2, Eqs. 5.49-5.57. Migrated from UrbanCanopy.jl@9200edd4 src/hydrology.jl:384 (`SurfaceRunoffInfiltration` @component). Implements the SIMTOP-based (Niu et al., 2005) runoff partition with frozen-soil-modulated saturated fraction (Eqs. 5.50-5.51), a maximum infiltration capacity built from top-layer matric-potential and saturation (Eqs. 5.52-5.55), and snow-aware surface infiltration (Eqs. 5.56-5.57). Observed-only: all 14 inputs are parameters and the seven outputs (f_frz_1, f_sat, s, v, q_infl_max, q_over, q_infl) are given by algebraic equations.