IV.T84 — Koide relation Q=2/3

The three charged lepton masses satisfy Q = 2/3 to all orders in the lemniscate topology; the proof uses the Z/3Z symmetry of L's three sectors (crossing, lobe 1, lobe 2) with 120-degree democratic matrix spacing, yielding Q = 2/3 independent of mass scale or Koide phase, with deviation O(alpha^2) ~ 5e-5.