Microphysical Bridge Coupling, Derived c₁ₑ₈₃₆₄, and Closure of the True One-Parameter Global Corridor in the Finite-Capacity Latency–Erasure Theory

We close the last open theoretical bridge of the late finite-capacity latency–erasure program by deriving the microphysical coupling that links the strong-field shell sector to the cosmological saturation sector and by converting the previously benchmarked bridge law into an exact one-parameter closure. Earlier stages of the program established the rotating shell benchmark and ringdown corridor, the primordial tensor and PTA sector, the reduced and true global-survival geometry, the Hubble-interface background-and-transport closure, the black-hole imaging interface, the four-arena constitutional tribunal, and the first populated numerical multi-window confrontation. What remained open was the unique theoretical gap already isolated by the global-survival papers themselves: the bridge coefficient relating the global corridor coordinate to the scalar saturation parameter . The present article derives that coefficient. The paper proceeds in four steps. First, we identify the microphysical origin of the bridge problem by expressing the strong-field shell sector and the cosmological saturation sector as two effective projections of one common capacity-balance law. Second, we derive the bridge coefficient from a microstate matching condition that links shell-capacity loading, saturation susceptibility, and the renormalized cosmological response. Third, we obtain the explicit bridge law not as a benchmark ansatz, but as a derived first-order reduction of the microphysical theory. Fourth, we use this result to close the true one-parameter global corridor of the late FCLET program and to replace the partially free bridge geometry of Article 89 by an exact derived one-parameter survival manifold. The result is decisive. The late FCLET program no longer requires an externally inserted bridge slope in order to connect strong-field and cosmological sectors. The bridge is now internal to the theory. In this sense, Article 94 is not another arena paper and not another numerical confrontation paper. It is the microphysical closure paper that turns the global corridor from a partially benchmarked relation into a derived structural law. It therefore supplies the missing theoretical anchor beneath Articles 89, 92, and 93.