nwvh/nextjs-discord-oauth ? reverse-engineered prompt

Build me a really simple Discord login demo with Next.js.

I want users to be able to sign in with Discord, stay signed in when they refresh the page, and log out cleanly. Keep it lightweight, with no database, and store the needed user info in local storage so it feels persistent. It should look decent with a simple modern layout, show the logged in Discord user details, and make it easy to see what is happening during login and logout.

Please make it easy to set up with a Discord app client ID from the environment file, and include clear handling for missing config so it does not just break silently. This is just a debug and learning tool, not something for production, so keep the implementation straightforward. If you need to check current docs for Discord or Next.js behavior, go ahead and look them up.