perf: aggregate homepage data and trim frontend loading

frontend/src/lib/api/client.ts

@@ -132,6 +132,14 @@ export interface ApiSiteSettings {
   paragraph_comments_enabled: boolean;
 }
 
+export interface ApiHomePagePayload {
+  site_settings: ApiSiteSettings;
+  posts: ApiPost[];
+  tags: ApiTag[];
+  friend_links: ApiFriendLink[];
+  categories: ApiCategory[];
+}
+
 export interface AiSource {
   slug: string;
   href: string;
@@ -398,8 +406,22 @@ class ApiClient {
   }
 
   async getPostBySlug(slug: string): Promise<UiPost | null> {
-    const posts = await this.getPosts();
-    return posts.find(post => post.slug === slug) || null;
+    const response = await fetch(`${this.baseUrl}/posts/slug/${encodeURIComponent(slug)}`, {
+      headers: {
+        'Content-Type': 'application/json',
+      },
+    });
+
+    if (response.status === 404) {
+      return null;
+    }
+
+    if (!response.ok) {
+      const errorText = await response.text().catch(() => '');
+      throw new Error(errorText || `API error: ${response.status} ${response.statusText}`);
+    }
+
+    return normalizePost((await response.json()) as ApiPost);
   }
 
   async getComments(
@@ -487,6 +509,24 @@ class ApiClient {
     return normalizeSiteSettings(settings);
   }
 
+  async getHomePageData(): Promise<{
+    siteSettings: SiteSettings;
+    posts: UiPost[];
+    tags: UiTag[];
+    friendLinks: AppFriendLink[];
+    categories: UiCategory[];
+  }> {
+    const payload = await this.fetch<ApiHomePagePayload>('/site_settings/home');
+
+    return {
+      siteSettings: normalizeSiteSettings(payload.site_settings),
+      posts: payload.posts.map(normalizePost),
+      tags: payload.tags.map(normalizeTag),
+      friendLinks: payload.friend_links.map(normalizeFriendLink),
+      categories: payload.categories.map(normalizeCategory),
+    };
+  }
+
   async getCategories(): Promise<UiCategory[]> {
     const categories = await this.fetch<ApiCategory[]>('/categories');
     return categories.map(normalizeCategory);