- Create UserSettingsLive to replace UserSettingsController
- Convert email/password forms to LiveView with proper form handling
- Add mobile session management (toggle alerts, revoke devices)
- Add require_sudo_mode on_mount hook to UserAuth
- Create dedicated live_session for sudo mode routes in router
- Keep UserSettingsController for email confirmation via token only
- Add MobileSessions.get_session/1 function for test support
- Update tests to match LiveView behavior (password update redirects to login)
- Remove old controller tests for email/password updates (now in LiveView)
