I really would prefer not to even use a CLI for this operation, since I think it's not well suited to the kind of interaction commits entail. A "staging area"

I really would prefer not to even use a CLI for this operation, since I think it's not well suited to the kind of interaction commits entail. A "staging area" is a useful concept, but it's not one that needs to exist outside the UI of whatever tool you're using to generate the commit.