OUCH v3.6 α-b₀ Degeneracy: Reconstructed Structural Audit

This technical note presents OUCH v3.6, the Operator for Universal Cosmological Hysteresis, as a reconstructed structural audit of the α–b₀ degeneracy in the late-time cosmological growth sector. The central question is whether the endpoint observable S₈(z=0) uniquely determines the underlying growth-response history. The reconstructed audit finds that endpoint S₈ constraints generate a projected α–b₀ ridge: one endpoint observable cannot independently determine both the amplitude parameter α and the saturation-shape coefficient b₀. Same-S₈ branches are not dynamically equivalent, since they may retain distinct F_irr(a) histories and distinct reconstructed fσ₈(z) trajectories. This release is not a production-code calibration, not an observational forecast, and not a first-principles derivation of b₀. It is intended as a public-scope structural audit and falsifiable technical note.