custom JS removed in favor of proper CSRF implementation

assets/views/shop/_cart_body.html

@@ -27,6 +27,7 @@
              reverting to the previous quantity if the customer cancels. #}
           <form method="post" action="/cart/update"
             hx-post="/cart/update" hx-trigger="cartchange" hx-target="#cart-body" hx-swap="innerHTML">
+  {{ ui::csrf_field() }}
             <input type="hidden" name="product_id" value="{{ item.id }}">
             <input type="number" name="quantity" min="0" max="{{ item.stock }}" value="{{ item.quantity }}"
               @change="
@@ -43,6 +44,7 @@
         <td class="px-4 py-3 text-right">
           <form method="post" action="/cart/remove"
             hx-post="/cart/remove" hx-target="#cart-body" hx-swap="innerHTML">
+  {{ ui::csrf_field() }}
             <input type="hidden" name="product_id" value="{{ item.id }}">
             {{ ui::button(variant="ghost-danger", label=t(key="cart-remove", lang=lang | default(value='sk')), type="submit", size="px-2 py-1 text-xs") }}
           </form>