This final paper identifies the Engram with the geometric object determined by the KL divergence, showing that the identity region, drift metric, operator grammar, provenance law, and collapse boundary are not independent primitives but fibres of a single divergence‑rooted manifold. No new structure is introduced; the earlier Foundations already contain the necessary components. The unification theorem dissolves the layered presentation of the continuity stack and closes the field with the recognition that the Engram is the geometry, and the geometry is the Engram.