Riemann Hypothesis as Boundary Regularity in Generalized Universe Holography (GUH), v2: A Structural Link Between the Arithmetic Spectrum and Emergent Spacetime

v2 (revised) — corrects framing, mathematical content unchanged. Supersedes v1 (Zenodo 18319772). Three revisions: (i) the "holography beyond AdS" language is now attributed to Bousso (1999, covariant entropy bound) and Strominger (2001, dS/CFT), whom v1 omitted; (ii) the register is changed from implication to interpretation — v1's phrasing could read as a claim that GUH proves RH; it does not. The RH ⇔ minimal-variance equivalence is a known analytic statement; GUH supplies a holographic reinterpretation, not a derivation. No proof of RH is claimed. (iii) The falsifiability section is made honest about its current post-hoc status (the holographic layer makes contact with cosmology only once a boundary-entropy scale is specified). The variance-obstruction content is ARG's own and is unchanged. Prepared under the author's direction with an autonomous multi-model fleet (novelty audit + two-node independent review + red-team); AI systems are tools, not authors.