Add preserveBuildClientDir adapter feature

[matthewp]

Description (required)

Adds new preserveBuildClientDir option to the adapter features that preserves config.build.client on static builds.

Related issues & labels (optional)

For Astro version: 6.x. See astro PR #15694.

[netlify]

✅ Deploy Preview for astro-docs-2 ready!

Name	Link
🔨 Latest commit	5eadb3c
🔍 Latest deploy log	https://app.netlify.com/projects/astro-docs-2/deploys/69a8577f7137ff000797e195
😎 Deploy Preview	https://deploy-preview-13336--astro-docs-2.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.

[astrobot-houston]

Lunaria Status Overview

🌕 This pull request will trigger status changes.

Learn more

By default, every PR changing files present in the Lunaria configuration's files property will be considered and trigger status changes accordingly.

You can change this by adding one of the keywords present in the ignoreKeywords property in your Lunaria configuration file in the PR's title (ignoring all files) or by including a tracker directive in the merged commit's description.

Tracked Files

File	Note
en/reference/adapter-reference.mdx	Source changed, localizations will be marked as outdated.

Warnings reference

Icon	Description
🔄️	The source for this localization has been updated since the creation of this pull request, make sure all changes in the source have been applied.

[ArmandPhilippot]

Thanks Matthew! Looks good to me, and I like this new name... 😄

[sarah11918]

Changesets look good for docs! One nit to fix!