FPX: Entropic Self‑Exhaustion and Centropic Endurance

This Field Physics extension formalizes the structural asymmetry between the centropic and entropic motion arcs. Both arcs are lawful and ontologically equal, but they differ in terminal range: centropy may, in rare cases, saturate into 🕳️ Zenon, while entropy collapses at ♾ Khaon and returns to ⚫ Aion only as static potential. The document defines: Entropic self‑exhaustion — the intrinsic dispersive limit of entropic motion, governed by CQ thresholds and the collapse into Absolute Dispersion. Centropic endurance — the capacity of coherent fields to persist above sustaining thresholds (θ₂), enabling patterned reintegration and, at high coherence, Zenon contact. Acclivous entropy — entropic motion that simulates centropic ascent but collapses under propagation fidelity tests. Return differential — the structural difference between patterned centropic return and static entropic return. Implications for morphogenetic thresholds, resonance immunity, cascade events, and recovery protocols are provided. This entry clarifies a foundational aspect of the Zenetist Field Physics corpus and resolves long‑standing ambiguities in the motion‑arc topology.