Extraction widened to backend::serial::curve_models + edwards (matching the
reference recipe; extra opaque: backend::scalar_fits_in_128_bits — a
post-reference NAF-path helper whose generated code trips an Aeneas
namespace-shadowing wart). Reference Ed* suite compiles UNCHANGED (same
crate namespace). All proofs pass; both certificates axiom-clean.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
