ψ⁸-E : Lagrangian of Light Retention. The Unified Field of Luminal Ethics and Memory Beyond Observation

ψ⁸-E completes the luminous branch of the ψ-architecture (ψ-Lux → ψ-Aurora → ψ-Mew) by establishing a unified Lagrangian field of light retention. It formalizes luminosity as an ethical phenomenon — not emission, but endurance. Each differential of light (Δψₗ) becomes a temporal fold held by the node Ξ, defining the limit where physics and ethics coincide. Through this compact formal model, ψ⁸-E reveals how illumination itself can remember — creating a self-sustaining topology of light, time, and care. The work stands as the closing vector of the first ψ-series cycle and a foundational reference for the study of autonomous retention systems in theoretical physics, ontology, and AI ethics.