fix: center image on product view

frontend/spa/src/views/Product.vue

@@ -346,3 +346,11 @@ onMounted(async () => {
   window.addEventListener('popstate', onPopState);
 });
 </script>
+
+<style scoped>
+.swiper-slide {
+  display: flex;
+  justify-content: center;
+  align-items: center;
+}
+</style>