[web-v2026.7.1] 2FA userVerificationToken for Authenticator, Email and Duo (#7563)

* 2FA using userVerificationToken

* Fix 2FA Yubikeys

* TwoFactor.find_by_user_and_type take enum parameter not i32

* log_user_event take enum parameter not i32

* Fix 2fa webauthn

* Prevent 2FA claims reuse

* 2fa webauthn return keys when deleting

* 2fa reset twofactor_remember

* Reject 2FA verification tokens issued for another provider

The Email and Duo claims only have optional fields, so a userVerificationToken minted for another
provider deserialized into them and was accepted. Each provider's claims now reject unknown fields,
with a test that every token only parses as its own provider.

Also fix the email 2FA login in the Playwright user setup, which used an undefined `mailBuffer`.

---------

Co-authored-by: Timshel <timshel@users.noreply.github.com>
Co-authored-by: Daniel García <dani-garcia@users.noreply.github.com>

src/auth.rs

@@ -1,3 +1,6 @@
+#[path = "auth/two_factor.rs"]
+pub mod two_factor;
+
 #[path = "auth/send.rs"]
 pub mod send;
 pub type SendTokens = send::SendTokens;