UDCT v7.12 Preregistration: Anisotropy and Screening-Length Boundaries of Signed Jeans Solutions in Hydrus I

This record preregisters the UDCT v7.12 numerical protocol for investigating anisotropy and screening-length boundaries of signed radial Jeans solutions in Hydrus I. Motivated by the previously reported v7.11 results, the study will examine constant velocity anisotropy β from 0 to 0.5 and screening lengths from 1 to 3 pc. It will compare five prescribed model variants with QUMOND controls, using frozen model inputs, grid-refinement checks, and predefined negative, positive-candidate, and indeterminate classifications. Sign-changing intervals will undergo adaptive threshold searches without assuming monotonicity or a unique transition. Negative radial pressure will be interpreted as incompatibility with the specified stationary Jeans closure. Positive pressure alone will not establish a physically admissible distribution function, dynamical stability, or agreement with observations. The protocol does not claim a universal Hessian threshold or a general exclusion of MOND. The uploaded package contains the preregistration PDF, Python runner, frozen dependencies, README, requirements, and SHA-256 checksums. This record specifies prospective tests and does not report v7.12 simulation results. Production runs are to begin only after public preregistration. GitHub:https://github.com/wspaik5/UDCT_v7.12_Preregistration_Jeans_Transitions DOI reserved for this record:https://doi.org/10.5281/zenodo.23280972 Previous v7.11 results:https://doi.org/10.5281/zenodo.23263099