moved blog posts out of content.ts for external management

app/blog/category/[category]/page.tsx

@@ -9,7 +9,7 @@ import BlogList from "@/components/BlogList";
  * links use the ?category= form so navigation stays consistent across both.
  * Unknown slugs 404: a real route can notFound(), a query param cannot.
  */
-export default function BlogCategoryPage({ params }: { params: Promise<{ category: string }> }) {
+export default async function BlogCategoryPage({ params }: { params: Promise<{ category: string }> }) {
   const { category } = await params;
   if (!category || !blogCategories().includes(category)) notFound();