fix(launch): fall back while concatenated scripts build

[kpal81xd]

What's Changed

• preflight the concatenated script cache before using it
• fall back to individual script URLs after two seconds, a cold-cache response, or a request error

Manual smoke test

1. Launch a classic-script project with Concatenate Scripts enabled and an empty cache; confirm launch continues with individual scripts within two seconds.
2. Reload after the cache warms; confirm the preflight returns 200 and the concatenated script is used.
3. Disable Concatenate Scripts and confirm no preflight request is made.

Checks

• I confirm I have read the contributing guidelines

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
editor	Ready	Preview, Comment	Jul 10, 2026 11:07am