SyntaxError: Could not find export 'ReadableStream' in module 'stream'

For disambiguity, what I'm referring to herein is WHATWG `ReadableStream` https://streams.spec.whatwg.org/#rs-class, not Node.js-specific `Readable`

When you do this

```
console.log(ReadableStream);
```

this is printed

```
[class: ReadableStream]
```

However, when trying to construct a `ReadableStream`

```
let z = 0;
const readable = new globalThis.ReadableStream({
pull(c) {
if (z === 5) {
c.close();
}
c.enqueue(new Uint8Array([z]));
++z;
}
});
```

this error is thrown

```
[class: ReadableStream]
Error: ReadableStream is not supported via global scope. Enable this by adding this to your code:
import { ReadableStream } from "stream";
globalThis.ReadableStream = ReadableStream;

```

Node.js `Readable` is not the same as WHATWG `ReadableStream`, and is not exported by `"node:stream"`

```
import * as streams from "node:stream";
console.log(streams);
```

```
{
Duplex: [function: Duplex],
PassThrough: [function: PassThrough],
Readable: [function: Readable],
Stream: [function: Stream],
Transform: [function: Transform],
Writable: [function: Writable],
default: [function: Stream],
finished: [function: finished],
pipeline: [function: pipeline]
}
```

`Duplex.toWeb()` does convert a Node.js-specific `Readable` to a WHATWG `ReadableStream`. We shouldn't need to do that if WHATWG `ReadableStream` is defined globally.

This needs clarifying.

Reproduce the globalThis.ReadableStream construction and inspect how the stream module exposes WHATWG ReadableStream versus Node.js Readable. Compare that behavior with the node:stream exports and Duplex.toWeb() conversion described in the report. Done means the supported behavior and required usage are clarified or the reported mismatch is resolved and covered by an appropriate test.

Written by the indexing model from the issue text.