Paper 57F: VSI–2 — Flux Concentration / Visibility Localization as an Organizer-Scale Constraint A governance-grade localization test following VSI–1 in PRIMER–COSMOS and PRIMER–UDS

This paper introduces VSI–2, a governance-grade key performance indicator designed to test whether astronomical visibility at organizer scales manifests as extreme flux concentration or as a bounded, distributed channel. Using JWST PRIMER–COSMOS and PRIMER–UDS catalogs, VSI–2 operationalizes visibility localization as a top-quantile short-band flux concentration measured within deterministic tile–redshift strata and evaluated against blocked permutation nulls with centered p-values. Under conservative WBIN null hardening, PRIMER–COSMOS exhibits a statistically significant, scale-localized negative governed excess, with the strongest deviation at organizer-scale neighborhood geometry. This result rejects a monotone “environment produces dominant cores” interpretation at the tested scales. Instead, it supports a constrained interpretation in which environment can increase visibility incidence without driving runaway core dominance, consistent with bounded redistribution across multiple emitting sites. VSI–2 functions as a discriminator that tightens the viable mechanism space without asserting a specific physical model, and it motivates the next escalation step to continuous cross-band persistence testing (VSI–3) under the same reproducibility and governance contract.