psi^8: Coordinate-Free Predictive Architecture under 100% Deviation — Retention Dynamics beyond Metric Collapse

This work introduces psi^8, a mathematically rigorous and coordinate-free predictive framework operating under the 100% deviation regime, where all external synchronizations collapse. Unlike conventional cosmological models tied to coordinates and calibration constants, psi^8 preserves structural differences internally through retention nodes (Xi) and a difference field evolving in pseudo-time (τ). We present the full theoretical formalism, the coordinate-free Lagrangian, and a reproducible pipeline for mapping raw inputs into Δψ-space without post-hoc tuning. Validation across multiple stress scenarios demonstrates instrument-level zero deviation, confirming psi^8 as a robust predictive engine. An astrophysical case study (Whirlpool Galaxy, M51) illustrates near-horizon retention and Eddington-scale continuity. Beyond cosmology, psi^8 provides an operational basis for deep-space navigation, post-collapse survival, and ethical AI systems that must preserve autonomy under uncertainty. By embedding ethics directly into retention dynamics, psi^8 reframes predictive practice as both scientifically rigorous and philosophically grounded.