Koide Hardware Statics in the Tension Field: The Mechanical 2/3 Equilibrium of Lepton Masses in TFD

This paper provides the first purely field-mechanical derivation of the Koide relation for lepton masses (electron, muon, tauon). Within Tension Field Dynamics (TFD), elementary particles are understood not as isolated points but as load points within an elastic field structure. By applying "Triangle Statics" (Truss Effect), it is demonstrated that the empirical 2/3 ratio of the mass sums is a direct result of mechanical force equilibrium within the tension field ϕ. The work provides an explicit, parameter-free formula for the tauon mass (mτ≈1776.9 MeV), which aligns with experimental values without any adjustments. Thus, quantum numerology is replaced by causal hardware statics.