feat: dynamic sitemap and robots.txt

app/robots.ts

@@ -0,0 +1,10 @@
+import type { MetadataRoute } from 'next'
+
+const BASE_URL = process.env.NEXT_PUBLIC_BASE_URL ?? 'https://kotobane.achmad.dev'
+
+export default function robots(): MetadataRoute.Robots {
+  return {
+    rules: { userAgent: '*', allow: '/' },
+    sitemap: `${BASE_URL}/sitemap.xml`,
+  }
+}

app/sitemap.ts

@@ -0,0 +1,39 @@
+import type { MetadataRoute } from 'next'
+import { getAllCategories, getArticles } from '@/lib/directus'
+
+const BASE_URL = process.env.NEXT_PUBLIC_BASE_URL ?? 'https://kotobane.achmad.dev'
+
+export default async function sitemap(): Promise<MetadataRoute.Sitemap> {
+  let categories: import('@/lib/types').Category[] = []
+  let articles: import('@/lib/types').Article[] = []
+
+  try {
+    const [cats, arts] = await Promise.all([
+      getAllCategories(),
+      getArticles({ limit: 1000 }),
+    ])
+    categories = cats
+    articles = arts
+  } catch {
+    // Directus not available — return homepage only
+  }
+
+  const categoryUrls: MetadataRoute.Sitemap = categories.map((cat) => ({
+    url: `${BASE_URL}/${cat.slug}`,
+    changeFrequency: 'daily',
+    priority: 0.8,
+  }))
+
+  const articleUrls: MetadataRoute.Sitemap = articles.map((article) => ({
+    url: `${BASE_URL}/${article.category.slug}/${article.slug}`,
+    lastModified: article.published_at ? new Date(article.published_at) : new Date(),
+    changeFrequency: 'weekly',
+    priority: 0.6,
+  }))
+
+  return [
+    { url: BASE_URL, changeFrequency: 'hourly', priority: 1.0 },
+    ...categoryUrls,
+    ...articleUrls,
+  ]
+}