nx_vessel_geometry_test.nx

nx_vessel_geometry_test.nx -- smoke for nx_vessel_geometry (C0). Proves the geometry -> thermal-twin -> certification design loop: - a 4 L / r=80 mm cylinder gets a sane height + area (1-2) - heat capacity matches water physics (~16744 J/K) (3) - insulation conductance is sane and DROPS with thicker insulation (4-5) - bigger volume -> bigger heat capacity (6) - CLOSED LOOP: the geometry-derived device CERTIFIES for yogurt (7) Exit code = failed assertion number; 0 = all pass.