mango-blossoms/modrinth-spoofer ? reverse-engineered prompt

Build me a small JavaScript tool that lets me spoof or switch the Modrinth user it looks like I am using, mainly for testing and experimenting.

I want it to be simple and calm, with a very small interface, and easy to run from the command line or by opening the main file. It should let me set a fake user identity, change it quickly, and show me what is currently active. If it needs any setup, keep it minimal and make the usage obvious in the README.

Please make it feel finished, not like a rough script. Handle bad input nicely, keep the code clean, and if you need to check current docs or examples online, go ahead and do that.