Make emoji picker adapt to narrow screens (e.g. phones)
Currently the emoji picker is fixed at 7 columns of emoji. This makes it too wide for phones such as the PinePhone or Librem 5, which both have effective display widths of 360 px (720 px, 2 x scaled) - only enough for 6 columns.
It would be great for the picker to reduce its column count as necessary to fit on phone form factors. The category bar would have to be updated too, e.g. to wrap to two columns or be scrollable.