Paper 57H: VPI–H — Mechanism Boundary for "Visibility Processing" A decision-grade consolidation of VSI–1/2/3 with preregistered falsifiers under strict governance

Paper 57H defines VPI–H, a decision-grade mechanism-boundary KPI for the “visibility processing” hypothesis class. It consolidates the VSI ladder from Papers 57E–57G at the preregistered operating point (θ, Δz) = (2.0′, 0.50): VSI–1 (conditional incidence), VSI–2 (suppression of dominance), and VSI–3 (bounded cross-band persistence detectable under WBIN0 but extinguished under WBIN6). VPI–H converts these governed operating-point readouts into a signed processor score and a fragility contrast, and applies preregistered rules to classify broad mechanism classes as compatible, disfavored, or ruled out. The scope is operational: VPI–H is a governance-grade boundary on mechanism space, not a claim of unique microphysics or a mass inventory. The paper promotes key controls to required falsifiers—symmetric slicing, geometry randomization within deterministic tiles, extinction robustness, band substitution, and complement-label tests—so artifact explanations are selectively broken while a true bounded channel, if present, remains. All results are traceable to published VSI artifacts and deterministic assembly of operating-point rows under strict governance.