The U+ code-point entry is a floating panel now, not a page of the
keyboard. Opening it replaces the keyboard with a small draggable,
resizable pad; closing it puts back whatever was there before, on the
layout it was left on. Its close key ends the entry rather than turning
floating off.

How see-through it is comes from the floating keyboard's own opacity
setting — one preference for panels that hover over your document —
while its position and size are remembered separately.

With a hardware keyboard the pad now comes up regardless: that case
hides the on-screen keyboard, which used to leave the code you were
typing with nothing showing it.
