Real Contractive Linearisation of the SCT Projective Transport Residual

Research Note 17 in the "Geometry of the Critical Line" programme. This note proposes a numerically supported mechanism for the high-energy stabilisation of the transport ratio R(λ,m) = M₂₁/M₁₁. An exact λ-variation identity is derived with a corrected sign, and the numerically inferred linearisation coefficient a(λ,m) := −∂_λR/(R − ρ) is found to be positive-real (arg a < 0.02 rad) in the tested window. This is consistent with contractive flow toward ρ(m) without phase twist. No arithmetic interpretation is claimed. Part of a 46-paper open-access programme. The programme does not claim to prove the Riemann Hypothesis.