Keybase GUI behavior with focus-follows-mouse

I use i3 tiling wm with focus-follows-mouse and the fact that the keybase window disappears when it loses focus makes it hard to use, since it's likely that I will "interact" with other windows as I move my mouse to wherever the pop-up pops up.

Reproduce the behavior with i3 and focus-follows-mouse, then trace the Keybase GUI window behavior when it loses focus. No source file or test is named; done means the window remains usable in this setup instead of disappearing when the pointer moves to another window.

Written by the indexing model from the issue text.