feat(blog): auto-detect cover.png when image not in frontmatter

Author: CalvinAllen

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

@@ -1,21 +1,40 @@
 ---
 import type { GetStaticPaths } from 'astro';
+import type { ImageMetadata } from 'astro';
 import { getCollection, render } from 'astro:content';
 import PostLayout from '../layouts/PostLayout.astro';
 
 export const getStaticPaths = (async () => {
   const posts = await getCollection('blog');
+
+  // Import all cover images from blog directories
+  const coverImages = import.meta.glob<{ default: ImageMetadata }>(
+    '/src/content/blog/**/cover.png',
+    { eager: true }
+  );
+
   return posts.map(post => {
     // Extract just the slug from the path (e.g., "2024/slug-name" -> "slug-name")
     const slug = post.id.split('/').pop() || post.id;
+
+    // Try to find a default cover image if none specified in frontmatter
+    let image = post.data.image;
+    if (!image) {
+      const coverPath = `/src/content/blog/${post.id}/cover.png`;
+      const coverModule = coverImages[coverPath];
+      if (coverModule) {
+        image = coverModule.default;
+      }
+    }
+
     return {
       params: { slug },
-      props: { post, slug },
+      props: { post, slug, image },
     };
   });
 }) satisfies GetStaticPaths;
 
-const { post, slug } = Astro.props;
+const { post, slug, image } = Astro.props;
 const { Content } = await render(post);
 ---
 
@@ -25,7 +44,7 @@ const { Content } = await render(post);
   date={post.data.date}
   categories={post.data.categories}
   description={post.data.description}
-  image={post.data.image}
+  image={image}
   youtube={post.data.youtube}
 >
   <Content />