seo: sitemap, robots, og tags

frontend/src/app/sitemap.ts

@@ -0,0 +1,65 @@
+import { MetadataRoute } from "next";
+import { getQuestions, getPatterns } from "@/lib/api";
+
+const BASE_URL = process.env.NEXT_PUBLIC_SITE_URL || "https://codetutor.example.com";
+
+export default async function sitemap(): Promise<MetadataRoute.Sitemap> {
+  const entries: MetadataRoute.Sitemap = [
+    {
+      url: BASE_URL,
+      lastModified: new Date(),
+      changeFrequency: "weekly",
+      priority: 1,
+    },
+    {
+      url: `${BASE_URL}/questions`,
+      lastModified: new Date(),
+      changeFrequency: "daily",
+      priority: 0.9,
+    },
+    {
+      url: `${BASE_URL}/categories`,
+      lastModified: new Date(),
+      changeFrequency: "weekly",
+      priority: 0.8,
+    },
+    {
+      url: `${BASE_URL}/patterns`,
+      lastModified: new Date(),
+      changeFrequency: "weekly",
+      priority: 0.8,
+    },
+  ];
+
+  try {
+    // Fetch all questions for individual pages
+    const questionsResponse = await getQuestions({ limit: 1000 });
+    for (const question of questionsResponse.items) {
+      entries.push({
+        url: `${BASE_URL}/questions/${question.slug}`,
+        lastModified: new Date(),
+        changeFrequency: "monthly",
+        priority: 0.7,
+      });
+    }
+  } catch {
+    // Continue without question pages if API fails
+  }
+
+  try {
+    // Fetch all patterns for individual pages
+    const patternsResponse = await getPatterns();
+    for (const pattern of patternsResponse.items) {
+      entries.push({
+        url: `${BASE_URL}/patterns/${pattern.slug}`,
+        lastModified: new Date(),
+        changeFrequency: "monthly",
+        priority: 0.6,
+      });
+    }
+  } catch {
+    // Continue without pattern pages if API fails
+  }
+
+  return entries;
+}