[hsusul]

The prerenderToNodeStream reference says onHeaders "receives a [Headers] instance". It doesn't. The Node.js stream API passes a plain object with a Link property, the same as renderToPipeableStream. Only the Web Streams APIs (prerender, renderToReadableStream) wrap the descriptor in new Headers(...).

The source is packages/react-dom/src/server/ReactDOMFizzStaticNode.js. prerenderToNodeStream types the option as onHeaders?: (headers: HeadersDescriptor) => void and passes options.onHeaders straight through. prerender in the same file is the one that calls onHeaders(new Headers(headersDescriptor)).

The wrong sentence was copied from the Web Streams pages in #8632. This PR swaps in the wording renderToPipeableStream.md already uses for the same callback.

Code that follows the current docs and calls headers.get('Link') throws a TypeError ("headers.get is not a function").

Test plan

Ran against published react-dom@19.3.1 on Node 24.9.0, with a component that calls preconnect('https://example.com'):

static.node prerenderToNodeStream: [object Object] instanceofHeaders=false keys=["Link"] Link=<https://example.com>; rel=preconnect
static.node prerender: [object Headers] instanceofHeaders=true keys=[] Link=<https://example.com>; rel=preconnect
static.edge prerender: [object Headers] instanceofHeaders=true keys=[] Link=<https://example.com>; rel=preconnect
server.node renderToPipeableStream: [object Object] instanceofHeaders=false keys=["Link"] Link=<https://example.com>; rel=preconnect
server.edge renderToReadableStream: [object Headers] instanceofHeaders=true keys=[] Link=<https://example.com>; rel=preconnect

yarn lint, yarn tsc, yarn lint-heading-ids and yarn deadlinks pass.

[github-actions]

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