V.D244 — Sector-Collapse Signature at the BH Threshold

At the NS→BH transition (M≳M_TOV): B-sector (EM) collapsed (electron degeneracy overcome at M>M_Ch), A-sector (Weak) collapsed (neutronization complete, beta-equilibrium), C-sector (Strong) active at confinement scale (neutron degeneracy supports up to M_TOV), D-sector (Gravity) at spherical brink (tau-Schwarzschild radius approaches physical radius, linking class about to form). Formalizes the implicit sector-by-sector status previously scattered across ch17, ch38.