Companion Data and Code for: Orientifold Dark Energy: Phantom Crossing from Signed Volumes in Type IIB Compactifications

Version 2 (September 22, 2026) Adds companion code and documentation:- mcmc_signed_volumes.py — Main MCMC analysis- figure_generation.py — Figure generation (CAMB)- growth_results.npz — sigma_8 from CAMB- dic_results.npz — DIC analysis- fig_corner_5param.pdf — Corner plot- README.md, summary.txt, tau_values.npy, R_hat.npy Posterior samples are provided separately.The manuscript PDF is unchanged from v1.