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/app/page.tsx

@@ -87,7 +87,7 @@ export default function Home() {
 
   return (
     <main className="min-h-screen p-8 max-w-4xl mx-auto">
-      <h1 className="text-4xl font-bold mb-8">Sebastian Zinkls - Blog</h1>
+      <h1 className="text-4xl font-bold mb-8">{process.env.NEXT_PUBLIC_BLOG_OWNER + "'s" || 'Anonymous'} - Blog</h1>
       <nav className="mb-6 text-sm text-gray-600 flex gap-2 items-center">
         {breadcrumbs.map((bc, idx) => (
           <span key={bc.path.join('/') + idx}>
@@ -148,6 +148,7 @@ export default function Home() {
           </div>
         );
       })()}
+      <hr className="border-t border-gray-200 my-8" />
       <div className="grid gap-8">
         {/* Folders */}
         {nodes.filter((n) => n.type === 'folder').map((folder: any) => (