chore: merge main, resolve biome formatting conflicts

Merge origin/main into feat/external-2fa-codes. Resolve formatting
conflicts caused by biome rollout; preserve both feature streams:
PR's external 2FA token + signing-session 2FA proof additions plus
main's RateLimit/RecipientExpired/signingReminders/date-auto-insert.

In complete-document-with-token.ts, drop the duplicate early
field-fetching block introduced when main moved that logic later
with date auto-insert support; keep the EXTERNAL_TWO_FACTOR_AUTH
check using derivedRecipientActionAuth.

packages/auth/server/lib/errors/error-codes.ts

@@ -17,6 +17,7 @@ export const AuthenticationErrorCode = {
   // TwoFactorMissingSecret: 'TWO_FACTOR_MISSING_SECRET',
   // TwoFactorMissingCredentials: 'TWO_FACTOR_MISSING_CREDENTIALS',
   InvalidTwoFactorCode: 'INVALID_TWO_FACTOR_CODE',
+  SignupDisabled: 'SIGNUP_DISABLED',
   // IncorrectTwoFactorBackupCode: 'INCORRECT_TWO_FACTOR_BACKUP_CODE',
   // IncorrectIdentityProvider: 'INCORRECT_IDENTITY_PROVIDER',
   // IncorrectPassword: 'INCORRECT_PASSWORD',