Controller for handling user session management.

This controller manages user login and logout operations, including:

• Creating new sessions via email/password authentication
• Handling post-registration and password update flows
• Session termination (logout)
• GET-based logout for direct URL access

Security Features

• Prevents user enumeration by not disclosing whether an email is registered
• Supports remember me functionality via UserAuth module
• Session renewal on login/logout to prevent fixation attacks