Sconnie This indicates that composer managed to download flarum successfully.
Generating autoload is something it only does after succesfully creating the project.
If this is the case, you should be able to copy the content of "download" to where you want your forum, then copy the content of /pockethold/3rdparty/flarum/ to the same place.
then delete the "public" folder.
Your issue here prompted me to launch a vps with aapanel, and when testing the master branch, it seems that the "cleanup" phase fails.
The cleanup code has not changed since last release though, and it works on the three vps setups I have used to test before I released this time :/