feat(plugin-rsc): expose Node.js stream APIs

[restareaByWeezy]

Closes #1162

The vendored react-server-dom packages include Node.js stream APIs that are faster than their Web Streams equivalents on Node.js, but they weren't exposed by plugin-rsc. This adds separate entry points for them.

What's added

New entry points that mirror the existing rsc and ssr entries but use Node.js streams:

// RSC server — pipeable Node.js stream
import { renderToPipeableStream } from '@vitejs/plugin-rsc/rsc.node'

// SSR client — consume Flight data from a Node.js Readable
import { createFromNodeStream } from '@vitejs/plugin-rsc/ssr.node'

Both entry points also re-export the Web Streams variants (renderToReadableStream, createFromReadableStream) so you can switch entry points without losing access to the existing APIs.

The existing Web Streams exports (@vitejs/plugin-rsc/rsc, @vitejs/plugin-rsc/ssr) are unchanged.

Files

• src/react/rsc.node.ts — low-level Node.js RSC server APIs (imports from server.node)
• src/react/ssr.node.ts — low-level Node.js SSR client APIs (imports from client.node)
• src/rsc.node.tsx — runtime RSC entry with renderToPipeableStream + manifest wiring
• src/ssr.node.tsx — runtime SSR entry with createFromNodeStream + preload/proxy wiring
• tsdown.config.ts — added new entry points to build