Boundary-Defect Charged-Fermion Masses and Fine-Structure Constant Derivation

This note consolidates a boundary-defect formation framework for charged-fermion masses, the fine-structure constant. Charged fermions are modeled as localized radial-angular-support boundary eigenmodes whose observed masses arise as squared stable-mode projection amplitudes. A one-anchor charged-fermion mass scheme uses the electron mass, discrete sector data, and a fine-structure constant input or module output to reproduce a charged-lepton and quark mass pattern at sub-percent central-value accuracy, subject especially to quark mass-scheme ambiguity. The fine-structure constant is then treated as an electromagnetic boundary-stiffness output through a finite conditional module for 𝛼−1.