1. Admin panel (admin.niyojewelle.com) sends requests to the backend API (api.niyojewelle.com)
2. Every request includes x-api-key: <your key> header for authentication
3. Backend checks the key against API_SECRET_KEY in its .env
4. Backend calls Shopify Admin API using SHOPIFY_ADMIN_ACCESS_TOKEN
5. Products/metafields are saved in Shopify + local PostgreSQL DB