COCM: correction of the Hubble tension claim, low-redshift oscillatory structure prediction, and robustness analyses

This technical note complements Vázquez González (2026e) (DOI: 10.5281/zenodo.20171261). (1) We correct an error in earlier versions of the COCM corpus: the claim that the oscillatory parametrisation explains ~87% of the Hubble tension was based on inflated parameters (A0=0.177). With the correct DR1 best-fit (A0=0.091, φ=-0.956), the modulation at z=0 is -1.52% and COCM does not resolve the Hubble tension. (2) We derive a new falsifiable prediction: the COCM oscillatory structure produces crossings H_COCM=H_ΛCDM at z=0.015, 0.156, and 0.296, with amplitude ~3-5% at the peaks — testable with existing DESI BGS data. (3) We report five additional robustness analyses: power spectral density of residuals (no significant peak at ω_z with n=14), cosmic-chronometer-only fit (signal vanishes without BAO, Δχ²=0.08, p=0.96), BAO acoustic scale (r_d unaffected, D_H varies ±4.5% point-by-point), large-scale structure (k_COCM≈0.003 Mpc⁻¹, ℓ_COCM≈46), and DR1 vs DR2 parameter comparison (phase differs by 106°, crossings shift). Related works:P1: DOI 10.5281/zenodo.19950582P2: DOI 10.5281/zenodo.19991607P3: DOI 10.5281/zenodo.20090596P4: DOI 10.5281/zenodo.20096465NT: DOI 10.5281/zenodo.20104113P5: DOI 10.5281/zenodo.20171261 (conceptual: 10.5281/zenodo.20123140)