a90c5c4d6f
Code review polish: - _signature_key/_encryption_key typed as RSAPrivateKey | None - sign() uses assert instead of type: ignore - test_oauth_signer_signs_with_rsa verifies signature against public key - Clarifying comments on %3D/%26 manual encoding and Task 3 imports Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>