Blazeiscoding/LeetLab ? reverse-engineered prompt

Build me a full stack coding practice app called LeetLab.

I want users to be able to sign up with email and password, verify with an OTP email, and stay logged in with secure cookies. After that they should be able to browse coding problems, search and filter by difficulty or solved status, open a problem page with a code editor, run code against test cases, submit solutions, and see clear feedback for each test case. Please also save code locally per problem and language so it comes back when they return.

Include user profile stats like submissions, solved count, language usage, and a streak calendar. Add playlist support so people can create playlists, add or remove problems, and track progress. Also build a monthly leaderboard with scoring based on problem difficulty.

I need an admin area for creating, editing, and deleting problems. Use a modern clean UI and make sure the app feels polished, with a command palette and useful keyboard shortcuts. If you need to check current docs for anything, look them up online first.