seo: sitemap, robots, og tags

frontend/src/app/patterns/[slug]/page.tsx

@@ -1,13 +1,39 @@
+import type { Metadata } from "next";
 import { getPattern, getQuestions } from "@/lib/api";
 import { QuestionCard } from "@/components/questions/question-card";
 import { Card, CardHeader, CardTitle, CardContent } from "@/components/ui/card";
 import { notFound } from "next/navigation";
 
-export default async function PatternDetailPage({
-  params,
-}: {
+interface PageProps {
   params: Promise<{ slug: string }>;
-}) {
+}
+
+export async function generateMetadata({ params }: PageProps): Promise<Metadata> {
+  const { slug } = await params;
+
+  try {
+    const pattern = await getPattern(slug);
+    const description =
+      pattern.description ||
+      `Learn the ${pattern.name} pattern with ${pattern.question_count} practice problems.`;
+
+    return {
+      title: `${pattern.name} Pattern`,
+      description,
+      openGraph: {
+        title: `${pattern.name} Pattern | CodeTutor`,
+        description,
+        type: "article",
+      },
+    };
+  } catch {
+    return {
+      title: "Pattern Not Found",
+    };
+  }
+}
+
+export default async function PatternDetailPage({ params }: PageProps) {
   const { slug } = await params;
 
   let pattern;