Replaces the `pyeasyencrypt` library with a more robust and standard
encryption implementation using `cryptography.hazmat`.
This commit introduces AES-256-GCM for encrypting and decrypting user
account passwords. The `add_account` endpoint now properly encrypts
passwords before database insertion.
Error handling has been added to the `get_user_accounts` endpoint to
manage decryption failures for legacy passwords, which will be returned
as "DECRYPTION_FAILED".
BREAKING CHANGE: The password encryption algorithm has been changed.
All previously stored passwords are now invalid and cannot be decrypted.
Karl
79a2f6e944