performance improvements

frontend/src/pages/posts/[slug].astro

@@ -7,6 +7,10 @@ const { slug } = Astro.params;
 const API_URL = (typeof process !== 'undefined' ? process.env.PUBLIC_API_URL : import.meta.env.PUBLIC_API_URL) || 'http://localhost:3000';
 
 interface CoverImage { url: string; alt: string }
+interface PostNeighbor {
+  slug: string;
+  title?: string;
+}
 interface PostDetail {
   slug: string;
   date: string;
@@ -18,10 +22,8 @@ interface PostDetail {
   reading_time: number;
   cover_image?: CoverImage;
   image_count: number;
-}
-interface PostInfo {
-  slug: string;
-  title?: string;
+  prev?: PostNeighbor;
+  next?: PostNeighbor;
 }
 
 function formatDate(d: string) {
@@ -36,35 +38,26 @@ function formatSlug(s: string) {
 let post: PostDetail | null = null;
 let html = '';
 let error = '';
-let neighbors: { prev?: PostInfo; next?: PostInfo } = {};
 
 try {
-  const [postRes, listRes] = await Promise.all([
-    fetch(`${API_URL}/api/posts/${encodeURIComponent(slug ?? '')}`),
-    fetch(`${API_URL}/api/posts`),
-  ]);
+  const postRes = await fetch(`${API_URL}/api/posts/${encodeURIComponent(slug ?? '')}`);
   if (postRes.ok) {
     post = await postRes.json();
     html = renderMarkdown(post!.content);
   } else {
     error = 'Work not found in the catalogue';
   }
-  if (listRes.ok) {
-    const list: PostInfo[] = await listRes.json();
-    const i = list.findIndex(p => p.slug === slug);
-    if (i >= 0) {
-      neighbors = {
-        prev: i > 0 ? list[i - 1] : undefined,
-        next: i < list.length - 1 ? list[i + 1] : undefined,
-      };
-    }
-  }
 } catch (e) {
   const cause = (e as any)?.cause;
   error = `Could not connect to backend at ${API_URL}: ${e instanceof Error ? e.message : String(e)}${cause ? ' (Cause: ' + (cause.message || cause.code || JSON.stringify(cause)) + ')' : ''}`;
   console.error(error);
 }
 
+const neighbors = {
+  prev: post?.prev,
+  next: post?.next,
+};
+
 const isAdmin = Astro.cookies.get('admin_session')?.value === '1';
 const displayTitle = post ? (post.title || formatSlug(post.slug)) : 'Work';
 ---