AddAuth extends the output of `bin/rails generate authentication` with the credentials it does not cover: passkeys, email-link sign-in, purpose-bound reauthentication and recovery. It adds hardened sessions, security mail and challenge providers, with shared Turbo/HTML pages and permitted no-JavaScript alternatives. It upgrades the generated User and Session models in place. Optional account lifecycle, Devise migration, provider-library integration and finite native sessions share the same account and session policies. Documentation: https://addauthgem.com.