Next step

Implement V3_grav (own rules, validated against XVI-P D01) and the ghost vertex (validated against D06/D13). Evaluate G01–G13 at the pole level, starting with the rows $c\varphi \varphi$ (G05, G06, G11, G12, G13) and $cc\bar{c}$/$ccK$ (G03, G04, G07, G09, G10). Assemble the projected ${\kappa }^3$ defect, reduce the counterterm domain, solve, and check ${\sigma }_0$ closure.