v2: fix fallback and VA redirects

[SamyPesse]

No description provided.

[github-actions]

Summary of the deployments:

Version 1 (production)

Version	URL	Status
Latest commit	https://936c838d.gitbook-open.pages.dev	✅
PR	https://pr2948.gitbook-open.pages.dev	✅

Version 2 (experimental)

Version	URL	Status
Vercel	https://gitbook-v2-3n9imj1c7-gitbook.vercel.app	✅
Cloudflare	https://ab596038-gitbook-open-v2-preview.gitbook.workers.dev	✅

Test content

Site	v1	v2
GitBook	https://936c838d.gitbook-open.pages.dev/docs.gitbook.com	https://gitbook-v2-3n9imj1c7-gitbook.vercel.app/url/docs.gitbook.com
E2E	https://936c838d.gitbook-open.pages.dev/gitbook.gitbook.io/test-gitbook-open	https://gitbook-v2-3n9imj1c7-gitbook.vercel.app/url/gitbook.gitbook.io/test-gitbook-open

[argos-ci]

The latest updates on your projects. Learn more about Argos notifications ↗︎

Build	Status	Details	Updated (UTC)
customers-v1 (Inspect)	👍 Changes approved	10 changed	Mar 8, 2025, 10:15 AM
customers-v2 (Inspect)	👍 Changes approved	19 changed	Mar 8, 2025, 10:17 AM
default (Inspect)	👍 Changes approved	5 changed	Mar 8, 2025, 10:17 AM
v2-vercel (Inspect)	🔘 Orphan build	588 added	Mar 8, 2025, 10:19 AM

[changeset-bot]

⚠️ No Changeset found

Latest commit: 1651d13

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR