H₀ as an Interface-Dependent Stress Test: Local Consistency Without Global Closure in Contemporary Cosmology

Persistent discrepancies in the inferred value of the Hubble constant (H₀) are commonly interpreted as evidence for unknown systematics or new physics beyond the standard cosmological model. In this work, we adopt a different perspective and treat the H₀ tension as a diagnostic stress test on the comparability of observational interfaces and inferential regimes. We show that current measurements of H₀ exhibit strong local internal consistency within individual observational and methodological domains, while simultaneously failing to admit a globally consistent closure across domains. This mismatch is not attributed to statistical noise or parameter degeneracy, but to interface-dependent limitations in cross-regime comparability. Within this framework, the H₀ tension is interpreted as a manifestation of global non-closure emerging from locally coherent but structurally non-integrable inference pipelines. No modification of underlying physical laws or cosmological dynamics is proposed. Instead, the analysis highlights the role of interface structure and aggregation constraints in shaping the limits of global cosmological inference. The results suggest that persistent tensions may signal structural boundaries of inference rather than unresolved physical discrepancies, motivating a diagnostic reassessment of how local consistency is extrapolated to global cosmological conclusions.