Any suggestions for getting back into the app on the server side? I'm willing to give the other suggestions a try but there is no point if I can't get back into the app to add media. These earlier ideas no longer work:

stop the server
./scripts/user delete user
./scripts/user add username password admin
start the server

You should be able to login then. If not, delete all users, restart server, use the browser to go to settings -> users and add a user there. Click on the username that appears on the list, switch the role to admin, set its password (it's random by default) and then press change. Then fully reload the page to authenticate as that user.