chore: add create user route

frontend-prep/src/api/api.ts

@@ -5,7 +5,7 @@
 // ✅ loginUser et registerUser retournent AuthResponse
 // ✅ sessionStorage (pas localStorage)
 
-const API_URL = "/api/v1";
+const API_URL = "http://localhost:8080/api/v1";
 import type {
     ConfirmReceptionResponse,
     CheckoutCartResponse,