Frontend (React + Tailwind)

Pages:
- Login (POST /api/auth/login)
- Products (insert form -> POST /api/products)
- Sales (insert form -> POST /api/sales)
- Reports (daily sales + daily stock status via /api/reports/*)
- Logout

Axios integration:
- withCredentials: true (uses express-session cookies)

Run:
1) Configure Vite + deps
2) Start backend then frontend

