SRP-6a with Argon2id, the password never leaving the device and
unlocking the account's key pairs (libsodium on devices); mandatory
TOTP with recovery codes, a 72-hour reset by mail as Proton has it, a
recovery phrase; data keys per store sealed to the account; studysets
private or not, private by default; email codes only for resets;
GitHub sign-in deprecated.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>