Paper CLIX: One-Octonion Tidal Disruption Streams, Presolar Grain Isotope Anomalies, and Galactic Chemical Evolution as a Unified G₂ Boundary-Crossing

We demonstrate that three independent 2026 observational results — the highest-resolution tidal disruption event (TDE) simulation to date (Kubli et al. 2026, ApJL 999: L40), anomalous nickel isotope enrichment in X-type presolar silicon carbide grains (NiCo paper, submitted), and the systematic 10–20% overproduction of Ni/Fe in all core-collapse supernova (CCSN) models relative to the Perseus Cluster (Leung et al. 2026, ApJ 1001: 72) — are unified manifestations of the same G₂ permutohedron boundary-crossing physics in the One-Octonion Brane-Bulk Framework. The TDE result is explained by the T2* coherence condition: rₓ₂* (stream) = √ (G × 0. 5 M_ / a₀) = 11, 253 rₓ₈₃₀₋, placing the stream far below disruption ☉ threshold and driving nozzle shock dissipation to zero (confirmed at 10 ⁵ fractional energy, Kubli et al. Fig. ⁻ 3). The Ni/Fe overproduction and grain anomaly share a single isobaric Co→Ni mechanism via H -sector ⁻ (square face) crossings of the G₂ permutohedron. The complete formula is zero-parameter: f₈ₒ₎₁₀ₑ₈₂ = 1 − (1 − √6/28 × (Co/Ni) ) ^Nbounce, where √6/28 is the κ=0→κ=−1 geometry cross-term (Paper ☉ CXXXVIII, Theorem 2), (Co/Ni) = 0. 52 is the measured solar abundance ratio, and Nbounce = 2–4 is the ☉ number of times the inner homologous core (M₈₍₍₄ₑ ≈ 0. 20 M_) crosses the T2* resonance boundary ☉ rₓ₂* = r₍ₒ = 12 km during bounce. This resonance is itself derived: H₂₎₋₋₀₏ₒ₄ = √ (Gρ₍ₔ₂) gives a₀₋₎₂₀₋ such that rₓ₂* (0. 20 M_) = 12 km exactly. The resulting IMF-weighted Ni/Fe ☉ excess is 10. 4%, centered on the observed 10–20% overproduction across all 24 Leung et al. models. Part of the One-Octonion Brane-Bulk Framework series. Anchor DOI: 10. 5281/zenodo. 19120873. Community: one-octonion-brane-bulk. Author: Bharathi Dasan Jagadeesan, M. D. , University of Minnesota. ORCID: 0000-0002-1143-941X.