Disentangling Calibration Bias and Ordered Structure in Type Ia Supernova Residuals: An Entropy-Guided Reanalysis of the Hubble Tension

The persistent discrepancy between locally measured and early-universe–inferred values of the Hubble constant H0 is commonly interpreted as evidence for new cosmological physics. I revisit this inference by explicitly separating two distinct effects present in Type Ia supernova (SN Ia) Hubble residuals: (i) ordered structure along observational axes and (ii) population-dependent calibration shifts in the distance scale. I introduce an entropy-based diagnostic sensitive to ordering-induced structure in residuals under an explicitly chosen sorting variable, and combine it with a cell-based intercept analysis applied to the Pan- theon+SH0ES compilation. I find that SN Ia residuals exhibit strong non-random organization when ordered by redshift, independent of standardization choices. Conditioning on host-galaxy stellar mass, however, induces a coherent global shift in the Hubble-diagram intercept while leaving redshift-ordered entropy largely unchanged. This orthogonality demonstrates that the dominant contribution to the Hubble tension arises from a calibration bias tied to host-galaxy properties rather than from redshift-dependent structure or a failure of the ΛCDM expansion history. My results show that ordered residual structure and distance-scale calibration are distinct phenomena and must be treated separately in cosmological inference.