Allow next-js integration

Hello,

After the recent changes, the calibration.html doesnt seem to be working anymore. Although I did not notice any changes as such in the calibration html file itself. Is this just me or are others facing the same issue?

Start by reproducing the reported problem with calibration.html and compare its behavior after the recent changes. The issue does not name a source file, test, or specific failure beyond the calibration page no longer working, and its title refers to Next.js integration. Done means the calibration page works again and the requested integration behavior is clarified.

Written by the indexing model from the issue text.