feat: implement bff layer

app/essays/page.tsx

@@ -4,7 +4,7 @@ import type { Metadata } from "next";
 import Link from "next/link";
 import { PageHeader } from "@/components/page-header";
 import { buildOgMeta } from "@/lib/og";
-import { prisma } from "@/lib/db";
+import { bffList } from "@/lib/bff";
 import { EssaysGrid } from "./essays-grid";
 
 export function generateMetadata(): Metadata {
@@ -17,10 +17,12 @@ export function generateMetadata(): Metadata {
 }
 
 async function getAllEssays() {
-  return prisma.essay.findMany({
-    orderBy: [{ group: "asc" }, { order: "asc" }],
-    select: { slug: true, title: true, year: true, group: true },
-  });
+  return bffList<{
+    slug: string;
+    title: string;
+    year: number | null;
+    group: string | null;
+  }>("/essays");
 }
 
 export default async function EssaysPage() {