feat(F-178): completed feature

project/apps/pos/src/app/(terminal)/page.tsx

@@ -117,7 +117,17 @@ export default function RegisterPage() {
     setSearching(true);
     setSearchError('');
     try {
-      const res = await posApi.searchProducts(q, config?.session?.storeId) as { items: SearchResult[] };
+      const normalized = q.trim();
+      if (/^\d{8,14}$/.test(normalized)) {
+        try {
+          const exact = await posApi.productByEan(normalized) as SearchResult;
+          setSearchResults([exact]);
+          return;
+        } catch (err) {
+          if ((err as { status?: number }).status !== 404) throw err;
+        }
+      }
+      const res = await posApi.searchProducts(normalized, config?.session?.storeId) as { items: SearchResult[] };
       setSearchResults(res.items ?? []);
     } catch (err) {
       setSearchResults([]);
@@ -145,6 +155,26 @@ export default function RegisterPage() {
     setSearchResults([]);
   };
 
+  const addSearchResultWithEnter = async () => {
+    const normalized = search.trim();
+    if (!normalized) return;
+    setSearchError('');
+    try {
+      if (/^\d{8,14}$/.test(normalized)) {
+        const exact = await posApi.productByEan(normalized) as SearchResult;
+        addToCart(exact);
+        return;
+      }
+      if (searchResults.length === 1 && searchResults[0]) addToCart(searchResults[0]);
+    } catch (err) {
+      if ((err as { status?: number }).status === 404) {
+        setSearchError(`No existe ningún producto con EAN ${normalized}`);
+      } else {
+        setSearchError(err instanceof Error ? err.message : 'No se pudo buscar el producto');
+      }
+    }
+  };
+
   const removeFromCart = (variantId: string) => {
     setCart(cart.filter(i => i.variantId !== variantId));
   };
@@ -300,6 +330,12 @@ export default function RegisterPage() {
             type="text"
             value={search}
             onChange={e => setSearch(e.target.value)}
+            onKeyDown={(event) => {
+              if (event.key === 'Enter') {
+                event.preventDefault();
+                void addSearchResultWithEnter();
+              }
+            }}
             placeholder="Buscar producto o escanear EAN…"
             className="w-full px-4 py-3 border-2 border-gray-200 rounded-xl text-lg focus:border-[#2D6A4F] outline-none"
             autoFocus