One-Octonion Brane-Bulk Framework — Methodological Audit Package v2.4 (a0 MOND chain traced end-to-end; section 9.3 and 12.4 flags discharged)

Version 2.4 of the OOB Methodological Audit Package. Single substantive addition over v2.3: addendum v2.0.26 discharges the a0 MOND-scale flags of section 9.3 ('derivation chain to omnibus not traced') and section 12.4 ('a0 MOND scale — derivation trace'). The chain (Paper XXXVI Master Equation, with inputs from Papers VII/XIII/XIX/XXXIV) is traced end-to-end and machine-verified (verify_a0_MOND_chain_2026_06_11.py, 13/13, bundled in this record): (1) per-sump T1 acceleration cH/2pi = c^2/(2pi R_H) — one T1 recovery cycle per Hubble circumference, the 2pi being the same CXXXI discrete-cell phase period that drives the Yang-Mills mass gap, f_III P2 coherence, and Schwinger n=1 (addenda v2.0.20/v2.0.22); (2) pre-QCD the free H- anti-sump cancels the H+ sump to (dM/M) cH/2pi ~ 6e-20 m/s^2; (3) at t_QCD ~ 1e-5 s the H- sector confines (residual leakage r_QCD/R_H ~ 7e-42), removing the cancellation EXACTLY — the same dM/M appears in numerator and denominator, so a0 = cH0/2pi identically, parameter-independent; (4) theorem: a0 = cH0/2pi iff baryogenesis (dM nonzero) AND QCD confinement, else no MOND. Empirical: -0.58 sigma (Planck H0) / -0.26 sigma (SH0ES) vs Famaey-McGaugh (1.2 +/- 0.27)e-10 m/s^2. Status: a0 DERIVED at the same epistemological level as T_sump = 5/H0 (structural relationship times universal H0 anchor). SIDE-FINDING: erratum registered on Paper XXXVI section 4 (cosmological-constant section): claims (Lambda_QCD/M_Pl)^4 ~ 1e-122 but actual ~ 2.3e-80, and equates rho_Lambda with (150 MeV)^4 whereas observed rho_Lambda^(1/4) ~ 2.3 meV; the a0 derivation (sections 1-3) is independent and unaffected. All v2.3 content (35-constant verification, addenda v2.0.1-v2.0.25) unchanged. Supersedes v2.3. Community: one-octonion-brane-bulk. Bharathi Dasan Jagadeesan, M.D., University of Minnesota CMRR. ORCID 0000-0002-1143-941X. CC-BY-4.0.