Hi,
You can use "request system storage cleanup dry-run" this will list out the logs and the files which it will remove
Then you can use "request system storage cleanup" to clean them
Again you can run the dry-run command to check if any logs and file left out
cleanup command will not remove the configurations
Another option would be to system zerioze, which will wipe out everything then you can apply the basic configuration
https://www.juniper.net/documentation/en_US/junos/topics/reference/command-summary/request-system-zeroize.html
Method confirm if any log files are present would be check "file list /var/log" path where by default all the log files are stored
thank you
Prabin