Dragging a four-pixel slider to change the power by five watts is a fussy
gesture, and the Flex and Yaesu consoles have had the wheel for a while —
an operator moving between them expects it.
React registers onWheel as PASSIVE, so preventDefault() there is ignored
and the panel scrolls under the pointer while the value changes; the
listener is attached natively instead, with the live values read through
refs. Both existing panels solved it the same way, so this is a third
copy turned into one shared component -- used by the new console only.
The other two are left alone deliberately: they work, they are in daily
use, and their styling differs in ways a merge would have to guess at.
Power steps 5 W a notch, matching the K3's own coarse step.
