• backend/

  • server.js - Express server and Firebase Admin SDK initialization.
  • package.json - backend dependencies and startup scripts.
  • auth/
    • routes.js - authentication API routes (/auth/google, /auth/email-signin, /auth/me).
    • middleware.js - token verification and request sanitization logic.
  • .env (not committed) - backend environment variables for Firebase credentials, port, and allowed frontend origin.

• frontend/

  • package.json - frontend dependencies and Vite scripts.
  • vite.config.js - Vite configuration for the React app.
  • index.html - app shell.
  • src/
    • main.jsx - app entry point.
    • App.jsx - root React component.
    • firebase.js - Firebase client SDK initialization and auth helpers.
    • components/AuthPage.jsx - login / sign-up UI and backend verification flow.
    • App.css, index.css, components/AuthPage.css - app styling.