sdcreceipt 4.3.0

Receipt 1.1: the same content signed twice, ES256 and ML-DSA-65 (FIPS 204,
post-quantum), by the issuer over the same 32-byte digest. Receipt 1.0 is
unchanged and verifies exactly as before. The issuer's design is in SDCStudio
design_docs/vsl/receipt-1.1-post-quantum-PRD.md.

Added

• verify accepts Receipt 1.1. Every listed signature must verify with
  the algorithm its alg names; a signature this tool does not implement, or
  one the version does not allow, is a failure, not a skip. A new check,
  signatures.algorithms, fails a Receipt that says 1.1 without both an
  ES256 and an ML-DSA-65 signature, even when no schema is passed.
• ML-DSA-65 keys load from a key document. The issuer publishes a second
  key (alg ML-DSA-65) beside the P-256 one; --keys admits it, and a
  signature whose key is the wrong type for its alg is reported on that
  signature. ML-DSA-65 signatures are decoded as strictly as ES256 ones: 4412
  unpadded base64url characters, 3309 bytes, nothing else.
• Five 1.1 conformance vectors (sixteen in all) and the 1.1 schema, from
  the issuer's kit.

Changed

• cryptography>=50.0 (was 42): ML-DSA-65 verification arrived in 48.0.0.

Install: pip install sdcreceipt==4.3.0 (PyPI). Earlier versions are listed in CHANGELOG.md.