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

server/mappers/homepageMapper.ts

@@ -0,0 +1,54 @@
+import { isObject } from '../utils/object';
+
+/**
+ * 将 Directus 返回的 Homepage 数据转换为 HomepageView 视图模型
+ *
+ * @param raw: 原始的 Homepage 数据
+ * @returns 转换后的 HomepageView 对象
+ *
+ * @example
+ * const view = toHomepageView(rawHomepage);
+ */
+export function toHomepageView(raw: Homepage): HomepageView {
+  const carousel = (raw.carousel ?? [])
+    .filter(isObject<HomepageFile>)
+    .map((item) => item.directus_files_id)
+    .filter(isObject<DirectusFile>)
+    .map((file) => file.id);
+
+  const products = (raw.recommend_products ?? [])
+    .filter(isObject<Product>)
+    .map((item) => {
+      const trans = item.translations?.[0];
+
+      const cover = isObject<DirectusFile>(item.cover) ? item.cover.id : '';
+
+      return {
+        id: item.id,
+        name: trans?.name ?? '',
+        summary: trans?.summary ?? '',
+        cover: cover,
+      } satisfies HomepageProductView;
+    });
+
+  const solutions = (raw.recommend_solutions ?? [])
+    .filter(isObject<Solution>)
+    .map((item) => {
+      const trans = item.translations?.[0];
+      const cover = isObject<DirectusFile>(item.cover) ? item.cover.id : '';
+
+      return {
+        id: item.id,
+        title: trans?.title ?? '',
+        summary: trans?.summary ?? '',
+        cover: cover,
+      } satisfies HomepageSolutionView;
+    });
+
+  return {
+    id: raw.id,
+    carousel: carousel ?? [],
+    recommendProducts: products ?? [],
+    recommendSolutions: solutions ?? [],
+  };
+}