how to copy jars or folders at svn repository to https://sourceforge.net/projects/project-name/files/
You check out the files and folders locally from svn and them upload them using any of the methods described on the SourceForge support page. If you don't know which method to pick use SFTP.
If you don't want to check out the files locally you can use the SourceForge Shell Service and check out and upload the files using the remote shell.