Add Authentication System

Implement secure user authentication system: $ARGUMENTS

Current Application State

• Framework detection: @package.json or @requirements.txt or @Cargo.toml
• Existing auth: !grep -r "auth\|login\|jwt\|session" src/ --include="*.js" --include="*.py" --include="*.rs" | wc -l
• Security config: @.env* (check for auth-related variables)
• Database setup: Check for user models or auth tables

Task

Implement comprehensive authentication system with security best practices:

Authentication Methods: Choose from username/password, OAuth 2.0, JWT, SAML, MFA, or passwordless based on $ARGUMENTS

Implementation Areas:

1. User Management - Registration, profiles, password policies, account verification
2. Authentication Flow - Login/logout, session management, token handling, middleware
3. Authorization System - RBAC, permissions, route protection, API security
4. Security Hardening - Password hashing, rate limiting, CSRF protection, secure cookies
5. Integration - Frontend components, API endpoints, database models, middleware

Security Standards: Implement OWASP authentication guidelines, secure session management, and proper error handling.

Output: Production-ready authentication system with comprehensive security controls and user-friendly interface.