fix(admin): update Category resolution type check in Products.tsx

frontend/admin-panel/src/pages/Products.tsx

@@ -350,7 +350,7 @@ export default function Products() {
                     <td className="py-4 px-6 text-gray-600 text-sm">
                       {typeof product.category === 'object' && product.category !== null
                         ? (product.category.nameFa || product.category.name || 'بدون دسته')
-                        : (product.category || 'بدون دسته')}
+                        : (typeof product.category === 'string' ? product.category : 'بدون دسته')}
                     </td>
                     <td className="py-4 px-6">
                       <div className="flex flex-col">