Add Mellat e-payment, videos/instructions CMS, and legacy domain lookup.

Store gateway credentials per business, initiate/verify Mellat at checkout, and resolve old CMS ids from domains in the migrate modal.

Co-authored-by: Cursor <cursoragent@cursor.com>

docs/website-api/AI_PROMPT.md

@@ -34,6 +34,10 @@ You are building a **Meshkee business website (storefront)**. You must use the M
 3. Catalog: categories, products, store-items, **user-products** (customer stock listings)
 4. Auth: register/login → store tokens. Optional: `POST /auth/send-otp` then `POST /auth/login-otp` (passwordless) or `POST /auth/reset-password` (forgot password). `POST /auth/verify-otp` only marks the cell verified (no tokens).
 5. Cart checkout with `addressId` or inline `shippingAddress` + `payment`
+   - For online pay: `payment.type = "e_payment_gate"`, `gatewayType` (e.g. `"mellat"`), and absolute `returnUrl`
+   - Response includes `payment.redirect` `{ method, url, fields }` — POST/redirect shopper to the bank
+   - Bank callback hits API then redirects to `returnUrl?status=success|failed&orderId=…`
+   - Enabled gateways: `GET /tenants/{domain}` → `ePayment`, or `GET /businesses/{businessId}/payments/methods`
 
 ### User products (customer listings)
 Public marketplace listings owned by customers — not catalog `products`.