The Interior Observer Cosmological Framework — Paper 29: The Branch Consistency Audit: Resolving the Assembly Gap, the Schur Definitive Package, and Direct Expansion-Rate Confrontation

Beginning from two premises — (1) the observable universe exists inside a Schwarzschild black hole, and (2) the physics inside the horizon is the same as outside — this paper resolves the assembly gap that has persisted since Paper 20 through a branch self-consistency audit, establishes the unique surviving observational branch, and confronts the IO framework with the most direct expansion-rate measurements available. The carried observational package (H₀ = 67.58, Ω_m = 0.349, Ω_k = −0.006) is shown to be internally inconsistent — a hybrid combining legacy-branch values with Schur-branch curvature. Two self-consistent branches are reconstructed; the Schur definitive branch (H₀ = 68.91, Ω_m = 0.336, Ω_k = −0.006) is the unique surviving prediction. Against 35 cosmic chronometer measurements and 13 DESI DR2 BAO points, the Schur branch (χ² = 42.48) outperforms the Planck ΛCDM fixed-parameter reference (χ² = 44.80) with zero continuously fitted parameters. The BAO Ω_m residual (1.19σ) is within normal statistical scatter. The assembly gap is closed as a bookkeeping error, not missing physics. Multi-AI adversarial collaboration: Claude (Anthropic), Codex/ChatGPT (OpenAI), Gemini (Google DeepMind). Full paper series available at https://zenodo.org/communities/interior-observer/