feat(metro-config, cli): CSS serializer (#22325)

# Why

In order to support static CSS in development mode, we need to update
the metro serializer to support returning the JS and CSS assets. We n

feat(metro-config, cli): CSS serializer (#22325)

# Why

In order to support static CSS in development mode, we need to update
the metro serializer to support returning the JS and CSS assets. We now
inline the CSS in the HTML before sending to the client, this allows for
testing how the website works with JS disabled. We use the same style
tag id to continue to support HMR for styles during subsequent updates.

This change also refactors how exports work to serialize JS and CSS at
the same time (i.e. after the native transformations).

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# How

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# Test Plan

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# Checklist

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- [ ] Documentation is up to date to reflect these changes (eg:
https://docs.expo.dev and README.md).
- [ ] Conforms with the [Documentation Writing Style
Guide](https://github.com/expo/expo/blob/main/guides/Expo%20Documentation%20Writing%20Style%20Guide.md)
- [ ] This diff will work correctly for `npx expo prebuild` & EAS Build
(eg: updated a module plugin).

---------

Co-authored-by: Expo Bot <[email protected]>

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feat(metro-config, cli): CSS support for Metro web (#21941)

# Why

This PR moves the CSS support from Expo Router over to
`expo/metro-config` behind a beta flag. This is because we need deeper
i

feat(metro-config, cli): CSS support for Metro web (#21941)

# Why

This PR moves the CSS support from Expo Router over to
`expo/metro-config` behind a beta flag. This is because we need deeper
integration with Expo CLI and Metro in order to emit static CSS files in
production bundles. CSS is required for media queries -> rehydration.

- Related: https://github.com/expo/router/pull/397
https://github.com/expo/router/pull/223

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# How

Instead of a babel transformer, we now use a custom "transformer" which
gives us the ability to add extra metadata to a Metro module on export.
This means we can pass the raw and processed CSS for writing to disk.

The development version of CSS still uses script injection via
JavaScript, meaning static rendering cannot currently be tested in
development.

CSS Modules are implemented (web-only currently) using lightningcss. The
export is generated to work with React Native for web. Consider the
following block:

```js
export default { ...StyleSheet.create({ container: { $$css: true, _: 'hashed-container-id' } }) }
```

CSS Variables are not currently hashed, enabling the user to define
variables in a global CSS file and access them in CSS Modules (subject
to change in order to support native). CSS variables are accessible from
the default export as strings: `styles['--color'] === '--color'`.


## Docs

I've chosen to document in the versioned metro doc instead of the
unversioned guide, this seems like a reasonable spot given the highly
experimental nature of this feature.


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How did you build this feature or fix this bug and why?
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# Test Plan

- Unit tests for conversion.
- [x] Test in/out for transformer.
- [ ] Test static export.
- TBD for E2E


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Please describe how you tested this change and how a reviewer could
reproduce your test, especially if this PR does not include automated
tests! If possible, please also provide terminal output and/or
screenshots demonstrating your test/reproduction.
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# Checklist

<!--
Please check the appropriate items below if they apply to your diff.
This is required for changes to Expo modules.
-->

- [ ] Documentation is up to date to reflect these changes (eg:
https://docs.expo.dev and README.md).
- [ ] Conforms with the [Documentation Writing Style
Guide](https://github.com/expo/expo/blob/main/guides/Expo%20Documentation%20Writing%20Style%20Guide.md)
- [ ] This diff will work correctly for `expo prebuild` & EAS Build (eg:
updated a module plugin).

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feat(cli): add `export` command (#17034)

* feat(cli): add export command

* Update CHANGELOG.md

* update tests

* Update packages/@expo/cli/CHANGELOG.md

Co-authored-by: Expo Bot <34669131+

feat(cli): add `export` command (#17034)

* feat(cli): add export command

* Update CHANGELOG.md

* update tests

* Update packages/@expo/cli/CHANGELOG.md

Co-authored-by: Expo Bot <[email protected]>

* reduce interface

* refactor

refactor

refactor

* refactor

* remove all merging code

* drop aliases

* Added asset saving tests

* refactor export code up

* Update env.ts

* Drop unused

* added e2e tests

* Dropped --quiet flag

* PR Feedback

* fix tests

* fix export tests

* Update export-test.ts

Co-authored-by: Expo Bot <[email protected]>

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