Update welcome post content and formatting; implement dynamic blog owner name in layout and post metadata; add author field to post structure and API routes.

src/lib/markdown.ts

@@ -18,6 +18,7 @@ export interface Post {
   summary: string;
   content: string;
   createdAt: Date;
+  author: string;
 }
 
 const postsDirectory = path.join(process.cwd(), 'posts');
@@ -50,6 +51,7 @@ export async function getPostBySlug(slug: string): Promise<Post> {
     summary: data.summary,
     content: processedContent.toString(),
     createdAt,
+    author: process.env.NEXT_PUBLIC_BLOG_OWNER || 'Anonymous',
   };
 }