MASTER SYNTHESIS NOTE — Cross‑Sector Integration and Unified Horizon Dynamics in the δI‑Substrate Framework (Sectors XIX → XXIII)

The Master Synthesis Note integrates Sectors XIX → XXIII into a single, continuous description of δI‑substrate horizon dynamics. It unifies emergent proper time, magnetar‑domain polarization invariants, the global δI–Horizon Manifold, extreme‑field collapse‑energy amplification, and the ultra‑global terminal‑state collapse surface into one coherent physical lifecycle. This synthesis demonstrates that horizon formation, amplification, and terminal‑state geometry arise from correlation‑flow and δI‑gradient structure rather than classical spacetime singularities. The Master Synthesis Note provides the complete, end‑to‑end collapse‑regime architecture of the Unified Information Substrate.