Stylesheets using `rel="preload" as="style"` are now flagged as render‑blocking

### FAQ

- [x] Yes, my issue is not about [variability](https://github.com/GoogleChrome/lighthouse/blob/main/docs/variability.md) or [throttling](https://github.com/GoogleChrome/lighthouse/blob/main/docs/throttling.md).
- [x] Yes, my issue is not about a specific accessibility audit (file with [axe-core](https://github.com/dequelabs/axe-core) instead).
- [x] Yes, my issue is not answered by [other FAQs](https://github.com/GoogleChrome/lighthouse#faq).

### URL

https://creativetouchrotherham.co.uk/

### What happened?

Lighthouse has started flagging all our CSS stylesheets as render‑blocking, even though each one is explicitly preloaded using `rel="preload" as="style"` in the HTML. Two of the stylesheets are also preloaded via the `Link` response header. Historically Lighthouse has never treated these preloaded stylesheets as render‑blocking, but recent Lighthouse runs consistently list them under “Render‑blocking resources” and attribute LCP delay to them.

### What did you expect?

Preloaded stylesheets (`rel="preload" as="style"` and/or `Link: <...>; rel=preload; as=style`) should not be classified as render‑blocking. Preload fetches the stylesheet early, and Lighthouse previously recognised this behaviour correctly. I expected Lighthouse to continue excluding these preloaded CSS files from the render‑blocking audit.

### What have you tried?

- Verified that all preload tags are present and correctly formed in the HTML.
- Confirmed that the server sends valid `Link: rel=preload; as=style` headers for the primary and secondary stylesheets.
- Checked MIME types, caching headers, and transfer sizes.
- Reproduced the issue across multiple Lighthouse runs in Chrome DevTools and pagespeed.web.dev
- Confirmed that no recent changes were made to the site’s preload strategy or CSS delivery.

### How were you running Lighthouse?

Chrome DevTools

### Lighthouse Version

13.2.0

### Chrome Version

149.0.7827.116

### Node Version

_No response_

### OS

Windows

### Relevant log output

```sh

```

Reproduce the report URL with Lighthouse 13.2.0 and inspect the Render-blocking resources audit output for the preloaded stylesheets. Trace how rel="preload" as="style" and Link response headers are classified, then verify that correctly preloaded CSS is no longer reported as render-blocking.

Written by the indexing model from the issue text.