Add SEO metadata, sitemap, robots, and JSON-LD for search ranking.

Ship canonical/Open Graph/Twitter tags, WebApplication schema, and landing copy aimed at audio-to-YouTube queries.

Co-authored-by: Cursor <cursoragent@cursor.com>

components/JsonLd.tsx

@@ -0,0 +1,23 @@
+export function JsonLd() {
+  const schema = {
+    "@context": "https://schema.org",
+    "@type": "WebApplication",
+    name: "Songs2VID",
+    url: "https://songs2vid.com",
+    operatingSystem: "Web",
+    applicationCategory: "MultimediaApplication",
+    description: "Online tool to convert audio files into YouTube videos.",
+    offers: {
+      "@type": "Offer",
+      price: "0",
+      priceCurrency: "USD",
+    },
+  };
+
+  return (
+    <script
+      type="application/ld+json"
+      dangerouslySetInnerHTML={{ __html: JSON.stringify(schema) }}
+    />
+  );
+}