Add website special-products source setting for storefronts.

Let businesses choose product vs store_item sourcing, defaulting from the store module, and expose it on tenant resolve and store-specials.

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

docs/website-api/AI_PROMPT.md

@@ -29,8 +29,8 @@ You are building a **Meshkee business website (storefront)**. You must use the M
 7. **Partner SMS** (`POST /public/sms/send`) is for external partner backends with an issued `X-Api-Key` only — not for normal storefront UI. See https://api.meshkee.com/docs/website/SMS.md
 
 ### Typical bootstrap sequence
-1. `GET /tenants/{domain}` → branding + `businessId`
-2. Homepage: business-info, **static-images**, sliders, category-groups, brand-groups, store-specials
+1. `GET /tenants/{domain}` → branding + `businessId` + `specialProductsSource` (`product` or `store_item`)
+2. Homepage: business-info, **static-images**, sliders, category-groups, brand-groups, store-specials (`source` repeats the tenant setting; items are store listings when `source` is `store_item`)
 3. Catalog: categories, products (`GET /products/{slug}` includes `relatedProducts`: same category then same brand, in-stock first), store-items (`name` instant search: in-stock first, then `updatedAt`), **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`