fix: issue with locale rewrites on pages router

[nicholasio]

Description of the Change

Closes #

How to test the Change

Changelog Entry

Added - New feature
Changed - Existing functionality
Deprecated - Soon-to-be removed feature
Removed - Feature
Fixed - Bug fix
Security - Vulnerability
Developer - Non-functional update

Credits

Props @username, @username2, ...

Checklist:

• I agree to follow this project's Code of Conduct.
• I have updated the documentation accordingly.
• I have added Critical Flows, Test Cases, and/or End-to-End Tests to cover my change.
• All new and existing tests pass.

---

Note

Ensures Next.js pages router creates proper rewrites for localized and default routes, while leaving app router behavior unchanged.

• Add locale-aware rewrite generation (plus non-locale default) for cache-healthcheck, block-library.css, feed, robots.txt, sitemap.xml, :sitemap(.*sitemap.*\.xml), and ads.txt
• Special-case sitemap stylesheet /:path(.*main-sitemap\.xsl) to generate both default and per-locale rewrites (no multisite prefix)
• Preserve multisite prefixes and host header checks across all generated rewrites; skip i18n rewrites when using the app router
• Add comprehensive tests covering pages vs app router, single/multisite, feed/sitemap/xsl handling, and host checks
• Add changeset for @headstartwp/next patch release

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🦋 Changeset detected

Latest commit: 6796e54

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@headstartwp/next	Patch

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Project	Deployment	Review	Updated (UTC)
headstartwp-app-router	Ready	Preview, Comment	Dec 29, 2025 1:06pm
headstarwp	Ready	Preview, Comment	Dec 29, 2025 1:06pm

[github-actions]

📦 Next.js Bundle Analysis for @10up/wp-nextjs-app

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🎉 Global Bundle Size Decreased

Page	Size (compressed)
global	83.62 KB (🟢 -42.45 KB)

Details

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[github-actions]

📦 Next.js Bundle Analysis for @10up/headstartwp

This analysis was generated by the Next.js Bundle Analysis action. 🤖

This PR introduced no changes to the JavaScript bundle! 🙌