MEON R2 V40: Zero-Parameter Hydro-Envelope Rotation-Curve Audit with Fixed Geometric Couplings

This Zenodo package contains the MEON R2 V40 patched audit bundle for a zero-parameter Hydro-Envelope rotation-curve model. Building on the V33 hard-pass result and the V38 lambda-replacement audit, the formerly fitted coupling amplitudes are replaced by fixed geometric constants, λ₁ = 1/128 and λ₂ = 1/(64π²). The V40 package performs an internal galaxy-level cross-validation against locked MOND using the archived V33 evidence chain. The final patched status is PASS_V40_INTERNAL_ZERO_PARAMETER_CV_PATCHED. The full-sample zero-parameter model retains the V33-level improvement, with Δχ² ≈ −1411.33 and conservative ΔBIC ≈ −1395.08 against locked MOND. Galaxy-bootstrap testing gives a negative Δχ² fraction of about 0.9808, indicating that the fixed-constant core remains robust under internal resampling. The package also documents the current limitation of external validation: available non-SPARC rotation-curve corpora inspected so far do not provide sufficient independent gas-component data required for a true external Hydro-Envelope blind test. Therefore, this release should be interpreted as a reproducible internal zero-parameter audit candidate, not as a completed claim of an established physical law. Independent external datasets with full baryonic and gas-gradient information remain required for further validation.