Secure cookie configuration

Always set appropriate security flags on cookies, especially those used for authentication or session management. At minimum, include:

1. HttpOnly - Prevents JavaScript access to the cookie, protecting against XSS attacks
2. Secure - Ensures the cookie is only sent over HTTPS connections
3. SameSite - Use Lax for cookies needed after redirects (like OAuth flows), or Strict for maximum protection when redirects aren’t needed

Example of properly configured cookie in an OAuth flow:

// Attach the session cookie to the response header with security flags
let cookie = format!(
    "{COOKIE_NAME}={cookie}; SameSite=Lax; Path=/; HttpOnly; Secure"
);

These settings significantly reduce the risk of cookie theft, session hijacking, and cross-site request forgery attacks.