Landing page init

Add iframe detection banner for third-party cookie blocking

Add full profile management features (avatar, inline edit, delete account)

some optimization

progress and cancel

Refactor email content generation and update email sending logic

refactor: migrate to modular architecture, add system documentation, and enhance batch processing stability

feat: implement complete password recovery flow with OTP verification and transactional email templates.

feat: implement robust security middleware, authentication system, and frontend UI components