Capillary Condensation 2D: Pore-Ensemble BJH Inversion

This is the 2D counterpart to the 3D single-pore Kelvin-equation simulator: instead of one cylindrical nanopore, this models a whole population of pores drawn from a log-normal pore-size distribution, each one independently condensing and evaporating according to the Kelvin equation's k=1 (adsorption) and k=2 (desorption) branches. Sweeping relative pressure P/P₀ through a full up-and-down cycle produces a volume-weighted ensemble isotherm with the classic hysteresis loop — and, uniquely to this 2D view, a live BJH-style derivative inversion reconstructs an estimated pore-size distribution directly from that isotherm's desorption branch, letting you compare the recovered distribution against the true one that generated it. Adjust the mean pore radius, distribution width and adsorptive gas to see how the reconstruction tracks the ground truth.