Flower card cannot display minus temperatures

[RH-Dreambox]

At temperatures below 0 degrees centigrade, the temperature does not show a minus sign.
This means that the temperature is incorrectly displayed as plus degrees.
Latest beta V2024.10.0-beta1

[Olen]

I think I see the reaason:

There is a regexp to remove the units from the sensor values:

                const display_state = card._hass.formatEntityState(card._hass.states[sensor]).replace(/[^\d,.]/g, "");

I don't have time currently to improve this, but will happily accept a PR