Is your feature request related to a problem?

• fix: use filepath for calculateHostUploadDirFullPath, fixes #7065 #7066

showed that we don't have adequate tests for upload_dirs.

• Needs to make sure that ../private_files works
• Needs to test the case of multiple upload_dirs
• Does mutagen get set up right? (where enabled) - should be a bind-mount for each upload_dirs