TUSCv3: Unified Empirical Addendum — Mechanical Floor, 40/60 Partition Ratios, and Substrate Viscosity

TUSCv3: Unified Empirical Addendum — Mechanical Floor and Partition Ratios DESCRIPTION:This technical addendum to the TUSCv3 framework formalizes the mechanical energy partitioning of the vacuum substrate. It provides predictive anchors for the 2.02% gravitational energy loss floor and the 1.22 kpc M31 velocity snap. This document establishes the 40/60 longitudinal-to-transverse energy partition as a first-principles derivation for observed astrophysical plateaus and consolidates the unified D-score metrics into the viscous plenum model. This work builds upon the empirical anomalies identified in the LIGO/Virgo GWTC-3 and early GWTC-4 datasets regarding mass-ratio-dependent energy loss. It references the 'Hubble Tension' (Riess et al., 2021; Planck Collaboration, 2020) as a secondary manifestation of substrate viscosity. Additionally, it incorporates the M31 rotation curve data from the SPARC database to demonstrate the meso-scale decoupling of transverse substrate modes. This addendum serves as the formal mechanical bridge between the TUSC core ontology and the unified Response Law governing gravitational dissipation.