jpm was tested against the other package managers own tests. I also used it so I know it worked there. Human or AI the same question matters. Just because someone wrote pnpm, how did you know it worked? Someone used it. jpm is MIT licensed, as is with no warranty, the same as npm, pnpm and bun. It is a week old so using it on a mission critical feature means you probably need to test it. A human written package manager can have bugs just the same.
the reason the authors of pnpm know something works as intended is because every line of code came from them and they can hold the model of its mechanics in mind. you can't.
I'm not particularly concerned about this - I am never going to use your thing.
But your answer is insufficient.