Electromagnetism and Gravitation as Chiral Boundary Readouts of a Majorana Bulk

Within the Quantum Gauge Theory of Time (QGT), spacetime ℝ⁴ is the observable boundary generated by a non-invertible projection Π: 𝓜⁵ → ℝ⁴ of a Majorana spinor Ξ = CΞ̄ on 𝓜⁵ = ℝ⁴ × S¹ (τ), governed by a single conservation law. Under projection, the two chiral sectors of Ξ separate into electromagnetism (η-channel) and gravitation (ξ-channel): not two independent fields, but two complementary boundary readouts of the same neutral field. The paper establishes four results. (i) The fine-structure constant emerges as the structural pole of the projection filter H (z) = P₄ (z) / (1 − αz), with no free parameters. (ii) The scale hierarchy αₖ = α · 10ᵏ organises five distinct physical regimes from the electromagnetic to the hadronic. (iii) The discrete renormalisation law for boundary coherence B₊+₁ = 2Bₖ^2/3 is derived, with global fixed point B* = 8. (iv) The unified field equation (γ^μ D_μ + αξ + iαηγ⁵) Ψ = 0 is obtained, of which QED and GR are the chiral limiting cases. The absolute dimensional scale belongs to ker (Π*) by a model-independent structural theorem. The complete spectral factor Fₙm = (2√5) ^ (5/2) φ²/ (9π²) is closed in Paper P13 (DOI: 10. 5281/zenodo. 19392738). Editorial revision (April 2026): citation keys, level labels, internal cross-references, and abstract language aligned with closed results.