How do you securely give credentials to a stand-alone Function node?

Well, you could maybe search the whole of GitHub for

"nodename":

Might work.

Node devs normally check the flows site for anything similar before settling on a package name. You can see the actual node names there. Not perfect of course.

Actually, a node name search extension to the flows site would be good.

The naming requirements were changed 4 years ago.
Here is a link to the requirement in the ‘Creating Nodes’ section of the NR documentation.