I need a clean, well-structured web application scaffold that I can grow feature-by-feature. The first release must already do four things flawlessly: • handle email-and-password sign-up, sign-in, logout and session persistence (secure hashing, validation, basic error handling included); • expose the authentication actions through documented API endpoints; • present a simple front-end with client-side routing and a couple of example components wired to those endpoints; • persist user data through a proper data model so I can add new tables/collections later without breaking existing code. Feel free to pick the modern open-source stack you know best (React + Node/Express, Next.js, Vue + FastAPI, Django, etc.) as long as it keeps the code readable and the build/run instructions minimal (think one-command setup on macOS, Linux and Windows). What I expect back: 1. Source code in a private Git repository. 2. A concise README that covers environment variables, initial migration/seed steps and how to run tests. 3. Postman or equivalent collection that proves every auth endpoint works. 4. A brief hand-off call or screen-share so we can walk through the folder structure and discuss how I should phrase future follow-up prompts to extend the app. If everything above checks out in your demo branch, I’m ready to green-light the next iteration immediately.