Temporary depends hackery.
Be like Emacs if we see a ~ in a path.

Which means drop everything before it and start in the user's home directory.
Properly add our configs.
Avoid freakout if we get bogus popup pos.
Proper variable face, nix comment-delimiter TODO.
Support ephemeral popups.

Such popups are automatically cleared when the user does anything, in the same
way that overlay status messages are cleared.