refactor: migrate to static export (CF Pages) + Next 16

- output: export → prerender to ./out, pure static (no SSR, no 1101 CPU errors)
- drop @cloudflare/next-on-pages (deprecated); Next 15.5.2 → 16.2.6
- force-static on ImageResponse (icon/og) + metadata (sitemap/robots/manifest) routes
- security headers → public/_headers; wrangler.toml pages_build_output_dir=out
- remove stopgap .npmrc legacy-peer-deps

Verified: npm run build EXIT=0, ./out has 8 HTML pages + icons/og/sitemap/health.
NOTE: CF Pages dashboard build command must be changed to `npx next build`
(framework preset: Next.js Static HTML Export).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: ShuttleLab

.npmrc

@@ -1,5 +1,5 @@
-export const runtime = "edge";
+export const dynamic = "force-static";
 
 export async function GET() {
-  return Response.json({ ok: true, runtime: "edge" });
+  return Response.json({ ok: true });
 }

app/api/health/route.ts

@@ -1,6 +1,6 @@
 import { ImageResponse } from "next/og";
 
-export const runtime = "edge";
+export const dynamic = "force-static";
 
 export async function GET() {
   return new ImageResponse(

app/icon-192.png/route.tsx

@@ -1,6 +1,6 @@
 import { ImageResponse } from "next/og";
 
-export const runtime = "edge";
+export const dynamic = "force-static";
 
 export async function GET() {
   return new ImageResponse(

app/icon-512.png/route.tsx

@@ -1,3 +1,5 @@
+export const dynamic = "force-static";
+
 import { ImageResponse } from "next/og";
 
 export const size = { width: 32, height: 32 };

app/icon.tsx

@@ -1,3 +1,5 @@
+export const dynamic = "force-static";
+
 import type { MetadataRoute } from "next";
 
 export default function manifest(): MetadataRoute.Manifest {

app/manifest.ts

@@ -1,6 +1,6 @@
 import { ImageResponse } from "next/og";
 
-export const runtime = "edge";
+export const dynamic = "force-static";
 export const alt = "JSON Shuttle - Format, validate, fix and escape JSON";
 export const size = { width: 1200, height: 630 };
 export const contentType = "image/png";

app/opengraph-image.tsx

@@ -1,3 +1,5 @@
+export const dynamic = "force-static";
+
 import type { MetadataRoute } from "next";
 
 export default function robots(): MetadataRoute.Robots {

app/robots.ts

@@ -1,3 +1,5 @@
+export const dynamic = "force-static";
+
 import type { MetadataRoute } from "next";
 
 export default function sitemap(): MetadataRoute.Sitemap {

app/sitemap.ts

@@ -1,13 +1,13 @@
 import type { NextConfig } from "next";
-import { setupDevPlatform } from "@cloudflare/next-on-pages/next-dev";
 
+// Static export → Cloudflare Pages (static output in ./out; matches yaml/pdf/image).
+// `next build` prerenders every route to static HTML — no SSR, no CF free-tier
+// 1101 CPU errors. Security headers live in public/_headers (next.config
+// `headers()` is unsupported under output:export).
 const nextConfig: NextConfig = {
-  /* config options here */
+  output: "export",
+  trailingSlash: true,
+  images: { unoptimized: true },
 };
 
-export default async (): Promise<NextConfig> => {
-  if (process.env.NODE_ENV === "development") {
-    await setupDevPlatform();
-  }
-  return nextConfig;
-};
+export default nextConfig;