Support Subresource Integrity (SRI)

Next.js supports Subresource Integrity (SRI) through `experimental.sri`, which generates integrity hashes for JavaScript assets at build time and adds them to the corresponding `` tags. However, Vinext currently does not appear to support SRI.

It would be useful for Vinext to support equivalent functionality, ideally through the existing Next.js-compatible configuration:

```js
export default {
experimental: {
sri: {
algorithm: 'sha384',
},
},
}
```

Start by tracing Vinext's handling of the existing Next.js-compatible experimental configuration and the build path that emits JavaScript assets and their script tags. Confirm how the configured SHA-384 algorithm should be applied, then verify that generated tags contain matching integrity hashes.

Written by the indexing model from the issue text.