RK-JLR — Principio de Realizabilidad Estructural

This preprint presents a structural analysis of the Collatz problem formulated as a discrete dynamical system with pulsating stability. The approach studies contraction properties in an elevated space of orbit differences and shows that, under an explicit stability hypothesis, nontrivial cycles are structurally excluded. The analysis reduces the problem to a single, explicit finite verification step. No claim of an unconditional classical proof is made beyond the stated assumptions. The framework is intended as a structural reduction and classification of the remaining obstruction.