refactor: 将Data到ViewModel的转换由App转移至Server端

- 将逻辑转移到Server端后，简化前端逻辑

app/pages/products/[slug].vue

@@ -37,16 +37,7 @@
   // 获取路由参数
   const id = route.params.slug as string;
 
-  const { data, pending, error } = await useProduct(id);
-
-  const rawProduct = computed(() => data.value ?? null);
-
-  const product = computed(() => {
-    if (rawProduct.value === null) {
-      return null;
-    }
-    return toProductView(rawProduct.value);
-  });
+  const { data: product, pending, error } = await useProduct(id);
 
   const breadcrumbItems = computed(() => [
     { label: $t('navigation.home'), to: localePath('/') },