Test REST API

Static mock endpoints — no real logic.

MethodEndpointDescription
GET/api/healthHealth check
GET/api/usersList users
GET/api/users/:idSingle user
GET/api/productsList products
GET/api/products/:idSingle product
GET/api/categoriesList categories
GET/api/ordersList orders
GET/api/orders/:idSingle order
POST/api/auth/loginFake login → returns static JWT
GET/api/settingsApp settings