singhsanket143/Auth_Service ? reverse-engineered prompt

Build me a simple authentication service for my app.

I want users to be able to sign up, log in, stay signed in, and log out safely. Make it handle password hashing, basic validation, and protected routes so only logged in users can access private data. If it fits naturally, include a way to refresh or renew sessions and return clear JSON responses for success and failure.

Keep it clean and easy to run locally, with sensible defaults and a small set of routes I can plug into another app. Add a few examples or tests if that helps show it working. Use current best practices for auth, and look up any current docs online if you need to.