The koji database does contain the file lists in some fashion.
You can see from the "info" link for an rpm on a "buildinfo" page.
e.g.
https://koji.fedoraproject.org/koji/buildinfo?buildID=180269
->
https://koji.fedoraproject.org/koji/rpminfo?rpmID=2041477
I bet some koji guru around here can write a database query to do
a "kojiquery -f /file/name" of sorts.
Thanks,
Roland