With output: "standalone", next build writes server.js under
.next/standalone but leaves generated static/public assets in the
project root, so starting the standalone server directly (e.g. via PM2)
404s on JS/CSS/font/favicon requests and /login stays stuck loading.
Add a postbuild step that copies .next/static and public into the
standalone directory, skipping the workspace-traced CLI build which
already copies its own assets.