There's not a way to do this, but it makes for a good feature request!
Right now you'd have to manually do some work to stitch it together.
The biggest hurdle may be in the "Automatically optimize when exporting" option for image resources, which for each scene-based export would find the maximum size the image is used at and potentially shrink the image down. So if two scenes use the same image at different sizes, you could wind up with a non-optimal image depending on how you merged it together. For this reason, I would recommend doing a single complete export, and using that as your base
Then, you would just need to move all the individual
*_hype_generated_script.js files into that one particular folder.
The final step would be taking all the
.html files and changing the script src to reflect the singular name of the
.hyperesources folder. (note: There are some setups where this alone may not be enough to work properly, and you may also need to search in the
*_hype_generated_script.js file and also replace the
.hyperesources folder name)