Thinkpads. I like the Fold https://csdvrx.github.io/ but it doesn't have ECC, so it's only 3/4 (the keyboard is not ideal, but it's a foldable, so I can bring my own keyboard, which grants the "keyboard" point)

The P7x P5x and some of the previous P1 have Xeons and ECC, so it's 4/4 core requirements.