fix: add Cache-Control no-cache for HTML pages to prevent stale CDN content

Bunny CDN was caching HTML pages, so after deploys the browser kept
loading old JS bundles with expired Server Action hashes. This header
tells the CDN to always revalidate with the origin. Static assets
(/_next/static/*) are excluded since they are content-hashed.

next.config.ts

@@ -47,6 +47,14 @@ const nextConfig: NextConfig = {
   },
   async headers() {
     return [
+      {
+        // * Prevent CDN/browser from serving stale HTML after deploys.
+        // * Static assets (/_next/static/*) are content-hashed and cached separately by Next.js.
+        source: '/((?!_next/static|_next/image).*)',
+        headers: [
+          { key: 'Cache-Control', value: 'no-cache, must-revalidate' },
+        ],
+      },
       {
         source: '/(.*)',
         headers: [