- Update version to v1.4.4
- Add explicit threat model documentation
- Document known limitations prominently
- Include air-gapped usage recommendations
- Polish all documentation for clarity and examples
- Update README, DEVELOPMENT.md, GEMINI.md, RECOVERY_PLAYBOOK.md
- Implement cv25519 PGP encryption/decryption
- Add Base45 encoding with CRC16 integrity checks
- Create SEEDPGP1 frame format for QR codes
- Support BIP39 passphrase flag indicator
- Add comprehensive test suite with Trezor BIP39 vectors
- 15 passing tests covering all core functionality