fix: display « tarif appliqué » on checkout page

The ``basketTotal`` partial expects ``$sale_channel`` as a top-level
view variable.  The cart page passed it correctly, but the checkout
page and the AJAX basket refresh only passed it nested inside
``$basket``.

app/Http/Controllers/Shop/BasketController.php

@@ -68,8 +68,10 @@ class BasketController extends Controller
 
     public function getBasketTotal($deliveryId = false, $deliveryTypeId = false)
     {
+        $basket = Baskets::getBasketTotal($deliveryId, $deliveryTypeId);
         $data = [
-            'basket' => Baskets::getBasketTotal($deliveryId, $deliveryTypeId),
+            'basket' => $basket,
+            'sale_channel' => $basket['sale_channel'] ?? null,
         ];
 
         return view('Shop.Baskets.partials.basketTotal', $data);