- Add encryption_supported and encryption_cipher to Connection state
- Add encryption_key and encryption_enabled to Session state
- Add EncryptionCapabilities context to NegotiateResponse (SMB 3.1.1)
- Derive encryption_key from session_base_key in session_setup
- Export derive_encryption_key as public method
- Fix Session::new() signature with 8 parameters
- All encryption tests pass (3 passed)