Zero-Parameter Lepton Flavor from S³ Spectral Geometry and Cl(9): A Pattern from Two Constants

This standalone condensed preprint focuses exclusively on dimensionless lepton flavor observables derived from \(S^3× Cl(9)\) spectral geometry. All Higgs, QCD and cosmological content from the earlier cross-sector preprint (DOI: 10.5281/zenodo.21794678) is removed. Two geometry-fixed constants \(p,q\) predict seven independent lepton quantities within ±1.5% experimental deviation, with clear near-term experimental tests via JUNO and DUNE. Full technical derivations, cross consistency checks and classification of theoretical open problems are included in Appendix A. Manuscript prepared for submission to Physics Letters B.