Bio-Cubic Universe — Paper VII DESI DR2 Confirmation of the Bio-Cubic Framework: The Hubble Tension Reduced to 2.51 Sigma with Six BAO Tracers MCMC v4 — 9 Parameters — 1,280,000 Samples — DESI DR2 BAO (z = 0.51 to 2.33)

DESI DR2: beta = 0. 196 +/- 0. 059 (3. 3 sigma) | H0: 5. 60sigma -> 2. 51sigma | ln (B12) = +13. 98 DECISIVE THE TRIPTYQUE HOLDS: g/lambda = 1. 80 | S8 + H0 + tauᵥide simultaneously n = 2. 019 (Z2 universality class — 7th independent confirmation) Abstract We present results from the fourth MCMC run (v4) of the Bio-Cubic cosmological model, incorporating for the first time the DESI DR2 BAO constraints (arXiv: 2503. 14738, Phys. Rev. D 112, 083515, 2025). The DESI DR2 dataset provides six BAO tracers from z = 0. 51 to z = 2. 33, including the first sub-percent BAO measurement at z > 2 from the Lyman-alpha forest, replacing the three BOSS DR12 tracers used in MCMC v3 (Paper VI). The key new result is a dramatic improvement in the Hubble tension resolution: with DESI DR2 constraints, the H0 tension is reduced from 5. 60 sigma (LambdaCDM) to 2. 51 sigma (Bio-Cubic v4), compared to 4. 19 sigma in v3. This improvement is driven by a significant upward shift in the decoherence parameter beta from 0. 089 +/- 0. 039 to 0. 196 +/- 0. 059 -- now detected at 3. 3 sigma from zero, constituting the first robust detection of this parameter. The spectral index n = 2. 019 is confirmed for the seventh time, establishing the Z2 universality class. The Bayesian evidence increases to ln (B12) = +13. 98 (decisive). The vacuum remains stable (betacrit margin 11. 1 sigma) and the GW prediction OmegaGW = 7. 15 x 10^-12 remains within the LISA 2034 detection horizon. The Triptyque -- g/lambda = 1. 80 simultaneously controlling S8, H0, and the vacuum lifetime -- is confirmed with DESI DR2 data.