feat(blog): improve blog overview teasers layout

Increases the line clamps for title and excerpt in the blog

overview grid. Also parses the markdown content to

auto-generate a fallback excerpt if omitted in frontmatter.

lib/blog.ts

@@ -4,6 +4,31 @@ import matter from 'gray-matter';
 import { mapSlugToFileSlug } from './slugs';
 import { config } from '@/lib/config';
 
+export function extractExcerpt(content: string): string {
+  if (!content) return '';
+  // Remove frontmatter if present (though matter() usually strips it out)
+  let text = content.replace(/^---[\s\S]*?---/, '');
+  // Remove MDX component imports and usages
+  text = text.replace(/<[^>]+>/g, '');
+  text = text.replace(/^[ \t]*import\s+.*$/gm, '');
+  text = text.replace(/^[ \t]*export\s+.*$/gm, '');
+  // Remove markdown headings
+  text = text.replace(/^#+.*$/gm, '');
+  // Extract first paragraph or combined lines
+  const paragraphs = text
+    .split(/\n\s*\n/)
+    .filter((p) => p.trim() && !p.trim().startsWith('---') && !p.trim().startsWith('#'));
+  if (paragraphs.length === 0) return '';
+
+  const excerpt = paragraphs[0]
+    .replace(/[*_`]/g, '') // remove markdown bold/italic/code
+    .replace(/\[(.*?)\]\(.*?\)/g, '$1') // replace links with their text
+    .replace(/\s+/g, ' ')
+    .trim();
+
+  return excerpt.length > 200 ? excerpt.slice(0, 197) + '...' : excerpt;
+}
+
 export interface PostFrontmatter {
   title: string;
   date: string;
@@ -46,7 +71,10 @@ export async function getPostBySlug(slug: string, locale: string): Promise<PostM
 
   const postInfo = {
     slug: fileSlug,
-    frontmatter: data as PostFrontmatter,
+    frontmatter: {
+      ...data,
+      excerpt: data.excerpt || extractExcerpt(content),
+    } as PostFrontmatter,
     content,
   };
 
@@ -70,7 +98,10 @@ export async function getAllPosts(locale: string): Promise<PostMdx[]> {
       const { data, content } = matter(fileContent);
       return {
         slug: file.replace(/\.mdx$/, ''),
-        frontmatter: data as PostFrontmatter,
+        frontmatter: {
+          ...data,
+          excerpt: data.excerpt || extractExcerpt(content),
+        } as PostFrontmatter,
         content,
       };
     })
@@ -95,7 +126,10 @@ export async function getAllPostsMetadata(locale: string): Promise<Partial<PostM
       const { data } = matter(fileContent);
       return {
         slug: file.replace(/\.mdx$/, ''),
-        frontmatter: data as PostFrontmatter,
+        frontmatter: {
+          ...data,
+          excerpt: data.excerpt || extractExcerpt(fileContent.replace(/^---[\s\S]*?---/, '')),
+        } as PostFrontmatter,
       };
     })
     .filter(isPostVisible)