Courant-Integral
- flux_1d_ppm
finite_volume
cartesian
scheme
O(h^3) interior; O(h) at active limiter constraints
PPM-based 1D flux-form transport face flux: 4th-order CW84 edge interpolation + Colella-Woodward (1984) §4 monotonicity limiter + Courant-fraction flux integral + ifelse upwind selection on the per-face Courant.