`Response.clone()` followed by `HTMLRewriter.transform(response)` deadlocks when the clone's body is consumed before the HTMLRewriter output. workerd kills the request with "your Worker's code had hung and would never generate a response".

Without HTMLRewriter, reading the clone first works fine — the tee branches are independent. HTMLRewriter appears to couple them, so the clone's branch can't be read unless the HTMLRewriter branch is also being consumed.

```js
export default {
async fetch() {
const response = new Response("

Hello

");
const clone = response.clone();
new HTMLRewriter()
.on("h1", { element(el) { el.setInnerContent("Rewritten"); } })
.transform(response);

// Hangs — tee branch for `clone` is blocked because HTMLRewriter
// holds the other branch and nothing is reading its output.
return new Response(await clone.text());
},
};
```

I think this is the root cause of [cloudflare/workers-sdk#7313](https://github.com/cloudflare/workers-sdk/issues/7313). The common pattern of `ctx.waitUntil(cache.put(req, response.clone()))` combined with `return new HTMLRewriter().transform(response)` deadlocks in `@cloudflare/vitest-pool-workers` tests, because `waitOnExecutionContext()` waits for `cache.put` (which needs to read the clone) before the test consumes the HTMLRewriter output.