Level_set

Sensible and latent heat flux density released by burning fuel, per Eqs. 4–5 of Mandel et al. (2011). Migrated from WildlandFire.jl@126976f2 src/level_set_fire_spread.jl:295 (`FireHeatFlux` @component). Observed-only: fuel_burn_rate, w_l, h_fuel, M_f are inputs (parameters); phi_h and phi_q are algebraic outputs.

Fuel consumption model: exponential decay of remaining fuel fraction F after ignition, per Eq. 3 of Mandel et al. (2011). Migrated from WildlandFire.jl src/level_set_fire_spread.jl:243 (`FuelConsumption` @component). The fuel-fraction ODE D(F) = -is_burning*F/T_f decays with time constant T_f when is_burning ≈ 1; the algebraic w0_effective = F*w0_initial feeds the FireHeatFlux component in the coupled WRF-SFIRE pipeline.