Paper 12 of the Interior Observer (IO) cosmological framework. An adversarial internal audit reveals that the assumed baryon fraction fb = 0. 25 (Paper 3) produces a 31. 6σ deuterium crisis at BBN. This paper resolves the crisis by introducing the Baryon Dictionary Principle — a new ontological axiom identifying baryons as the gauge-coupled subset of geometric Oppenheimer-Snyder dust, fixing fb = 2γ/x = 0. 313 from the Ashtekar-Barbero connection structure. A discrete α-ladder of geometric exponents demonstrates that the 1-form exponent α = 1 is the unique projection scaling consistent with observed D/H, and retroactively explains Paper 3's BAO-optimized value fb = 0. 254 as the curvature exponent α = 3/2. A seven-point γ-scan proves the baryon correction is rational (F = ⟨K⟩x/ (8γ) = 1. 381) rather than exponential, with the exact identity fb × F = ⟨K⟩/4 yielding the master formula ωb, eff = (ln Δ/4) × ωₘ, geom. Results: θ* at −0. 5σ, ℓ₁ = 220. 0, R at −0. 3σ, D/H at −1. 2σ (improved from +31. 6σ), Yₚ at +0. 6σ, BAO χ² = 19. 8 (modestly lower than ΛCDM's 22. 0). Kill Shot 1 (ruler split): resolved. Kill Shot 2 (curvature Ωₖ = −0. 006): survives, testable by Euclid DR1 October 2026. Kill Shot 3 (frame split): confirmed. Five of six observables pass within 2σ with zero continuously tunable parameters.
David Fife (Tue,) studied this question.