Support buildEnd hook for react-router.config.ts

[mparq]

What is the location of your example repository?

No response

Which package or tool is having this issue?

Hydrogen

What version of that package or tool are you using?

2025.7.0

What version of Remix are you using?

RR7

Steps to Reproduce

Add a buildEnd hook to react-router.config.ts Run shopify hydrogen deploy.

Expected Behavior

The buildEnd hook should run after the react router build completes.

Actual Behavior

The buildEnd hook is bypassed by hydrogen CLI at this time. See #3252

This prevents hooks like sentry's integration for uploading source maps from the react router build and removing them before deploying to hydrogen. See https://github.com/getsentry/sentry-javascript/issues/17885.