Action Corridor from Metric Pressure: Least-Residue Selection, Stationarity, and the Euler–Lagrange Slot

A forced derivation of least-residue (action) selection from refinement-stable bookkeeping. This paper continues the forced sequence by showing that once a quadratic curvature size functional and dualization are forced, a global, partition-independent scalar ledger is pressured as the minimal selection rule among corridor-admissible configurations. The resulting “action corridor” selects configurations by least-residue (minimizing accumulated quadratic size) without importing manifolds, integrals, or calculus limits as primitives. Expressing least-residue using only corridor-legal first-order perturbations pressures an adjoint comparison operator and yields a local Euler–Lagrange-type slot, presented as an adjoint/paired form of the previously forced dynamical balance constraint.