Fix: Security enhancements and improvements

[Crevmick]

This commit addresses several security vulnerabilities and improves the overall robustness of the application.

Key changes include:

• Implemented a secure password reset functionality using OTP.
• Secured the admin secret comparison during registration against timing attacks using crypto.timingSafeEqual.
• Improved error handling in the JWT authentication middleware and corrected user data extraction from tokens.
• Added CSRF protection (using csurf) to the logout route, which was also changed from GET to POST.
• Strengthened input validation for user registration and other authentication flows using express-validator.
• Identified other areas in the codebase that require input validation enhancements.