The neutrino is proposed to be a brane-fabric scar a topological defect frozen into the brane fabric from the Big Bang nucleation event, rather than a con- ventional focal deceleration zone (mass) or interface wave mode (charge, spin). The scar is a region of the brane that was permanently deformed during the H+/H−colli- sion and never recovered to its equilibrium geometry. The neutrino mass mν ∝H(t) is time-varying, scaling with the Hubble parameter. Neutrino oscillation arises from the precession of the scar topology between three distinct deformation modes (the three avours). The exclusive left-handedness of neutrinos follows from the chirality of the H+ sector: the scar is oriented in the H+ direction of the Fano plane, which has a unique handedness. The DESI DR2 upper limit Σmν < 0.0642 eV creates tension with the oscillation lower limit Σmν > 0.059 eV; this tension dissolves in the sump framework because cosmological and oscillation measurements probe mν at dierent epochs when H(t) had dierent values.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.