And… I was making it much harder on myself than it needed to be.
Once I was logged in, the install library command with the correct library name took care of everything without adding in the folders and files for the library manually
fwiw, i have a work item to improve error handling / reporting in those scenarios (cli-driven commands like login / logout, cloud flash, etc). for now, keep an eye out for notifications (the bell icon in vscode’s status bar bottom-right) and when in doubt click “view log”.