ESSC_v29 Cosmology Note 1: Redshift-Dependent Opening of the Conversion Route

This note presents the first cosmological translation of the ESSC (Elastic Spacetime with Scale-Dependent Coupling) gate framework after ESSC v28. The purpose of this work is not to replace standard cosmology, identify the physical nature of dark matter, or claim a completed solution to existing cosmological tensions. Instead, the note advances a narrower structural proposal: cosmic evolution may be interpreted as the redshift-dependent history of access to a finite-width conversion route toward stable partial closure. Within this reading, the universe is not described simply as moving from openness to closure in a single uniform way. Rather, it is treated as an epoch-dependent landscape in which a geometrically admissible route may be more or less accessible to physical systems. This leads to a reinterpretation of cosmic noon. Instead of defining cosmic noon only as an activity peak, the present note proposes that it may be read as the epoch range in which success-band occupancy becomes maximal, namely the interval in which the largest fraction of systems can access and remain within a corridor of stable partial closure. The note also introduces a cautious entry into the dark sector, Lambda-CDM, and Hubble-tension-related discussion. In the present formulation, the strongest stopper identified in ESSC v28 is not equated with dark matter itself, but is read more cautiously as a halo-side suppression carrier or structural brake. Accordingly, this note does not claim a replacement of standard cosmology. It instead proposes a structural translation layer that may later support comparison, refinement, or rejection. This work should therefore be read as a conceptual and structural cosmology note: a first step in extending the ESSC gate logic from galactic conversion structure toward cosmological interpretation.