Cannot find module 'react' in Docker runner: use-sync-external-store/shim leaves __require('react') unresolved in SSR chunk

Bug Report

When using Nitro (via TanStack Start) in a pnpm monorepo with @auth0/auth0-react and a workspace package that uses use-sync-external-store/shim, the built SSR bundle contains an unresolved __require("react") call. This fails at runtime in any Docker runner stage where node_modules is not present.

Reproduction

https://github.com/psachs-alto/nitro-rolldown-repro

git clone https://github.com/psachs-alto/nitro-rolldown-repro
cd nitro-rolldown-repro
docker build -t repro .
docker run -p 3000:3000 repro
curl http://localhost:3000/

Error

Error: Cannot find module 'react'
Require stack:
- /app/.output/server/_ssr/app-<hash>.mjs
    at Module._resolveFilename (node:internal/modules/cjs/loader:1456:15)
    ...
  code: 'MODULE_NOT_FOUND',
  requireStack: [ '/app/.output/server/_ssr/app-<hash>.mjs' ]

Root Cause

Rolldown splits the SSR bundle into multiple chunks. When @auth0/auth0-react is present, Auth0 + React are bundled together into _libs/auth0__auth0-react+react.mjs, which exports an inlined require_react. However, use-sync-external-store/shim (coming from a separate workspace package) ends up in a different SSR chunk (_ssr/app-*.mjs) that does not have access to the inlined React. Instead it contains:

var require_use_sync_external_store_shim_production = /* @__PURE__ */ __commonJSMin(((exports) => {
    var React = __require("react"); // __require = createRequire(import.meta.url)
    ...
}));

__require is createRequire(import.meta.url) — a real Node.js require(). The Nitro runner stage only copies .output/ (not node_modules), so require("react") has nothing to resolve and throws.

Note: nf3 already handles this for tslib by copying it into .output/server/node_modules. react needs the same treatment when it appears as an implicit CJS external in @__PURE__ factory wrappers.

Workaround

After pnpm run build, copy React into the server output:

node -e "
  const fs = require('fs'), path = require('path');
  const r = path.dirname(require.resolve('react/package.json'));
  fs.cpSync(r, '.output/server/node_modules/react', { recursive: true, dereference: true });
"

Environment

Clone the linked nitro-rolldown-repro repository and run its Docker build, then inspect the generated .output/server SSR chunks and node_modules handling. Start from the unresolved __require("react") in the SSR chunk and compare it with the existing tslib treatment. Done means the Docker runner starts and curl http://localhost:3000/ succeeds without node_modules outside .output.