Wave-History Time-Rate Modulation in the Enchan Field

This record contains the Version 1.0 manuscript and reproducibility package for Wave-History Time-Rate Modulation in the Enchan Field. The work formulates and executes a synthetic, dimensionless 1D feasibility test of whether a prior localized perturbation in the implemented Enchan field leaves a time-dependent metric history that changes the proper-time frequency ratio of later test probes. At the finest tested ray and proper-time discretization, the measured shift is -6.016988e-4 and the first-order variational metric prediction is -5.784390e-4, a 3.87% relative difference with the same sign. The static control is at machine precision. However, the mu=1 and no-V' controls retain nonzero and larger modulation, so the full predeclared GO classification is not satisfied and Enchan-specific necessity or uniqueness is not established. Field-evolution timestep convergence and spectral/timbre distortion remain untested. This is not an observational comparison or empirical confirmation, and it does not establish that ordinary acoustic sound couples to the Enchan field in nature. The deposit provides the final PDF and a reproducibility archive containing code, frozen-model and parameter-provenance records, run log, figures, bibliography, SHA-256 manifest, README, and LICENSE. The archive includes the compiled manuscript and LaTeX source together with the reproducibility materials.