feat: admin product views column (always 0 until backend tracks it)

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

BACKEND-API-REFERENCE.md

@@ -539,7 +539,15 @@ Either way, the *authoritative* amount charged (`createCartPayment`'s `amount`,
 
 **Ask:** nothing new beyond what §10/§11 already ask for — once a real `AdminOrdersApiGateway` is bound, this feature starts working with no additional frontend change. Flagging here only so nobody spends time debugging "why doesn't the notification ever fire" against the mock.
 
-### 12.9 Trending search terms
+### 12.9 Admin product view counts
+
+**Gap:** Admin Products (§8) runs on a fully separate mock domain from the storefront's live catalog — `AdminProduct.visits` is a new field added to support a "Views" column in Admin Products, but the mock gateway always defaults it to `0` because there is no real tracking source available to the admin domain today. This is unrelated to the storefront's `Item.visits` field (§6, `/items/{id}`), which is live-wired but never displayed anywhere in the UI.
+
+**Ask:** two options, not mutually exclusive:
+1. Once admin Products gets a real backend (§10 step 4), include a per-product view/visit count in the response.
+2. Bridge `AdminProduct.visits` to the storefront's already-live `Item.visits` by product id, if a unified product identity exists between the storefront and admin domains — smaller change than building new tracking infrastructure.
+
+### 12.10 Trending search terms
 
 **Gap:** `SearchTrendingService.loadTrending()` is a stub returning `of(null)` - no trending-searches endpoint exists. It already degrades gracefully (UI hides the trending section rather than showing an error), so this is purely a missing-feature gap, not a bug.