fix(icom): the live radio names MY_RIG, and a manual take records it too

Two halves of the same station confusion. The entry form pre-filled MY_RIG
from the per-band default on every band change, so the log-time priority (the
radio that is keying beats the radio that was planned) never ran — the field
was no longer empty by the time the backend looked. The form now asks the
active radio first, through a new ActiveRadioMyRig binding.

And the manual record button started its capture from the From-radio sound
card unconditionally, where the automatic recorder already knew a network
Icom's audio is pushed from the 50003 stream: a manual take on the IC-7760
was a faithful recording of the Flex's DAX. Same source rule for both, and
the button is offered with no sound card at all when the network stream is
the source.

app_radios.go

@@ -235,3 +235,12 @@ func (a *App) activeRadioMyRig() string {
 	}
 	return ""
 }
+
+// ActiveRadioMyRig exposes the connected radio's MY_RIG to the frontend, which
+// pre-fills the entry form's My-station fields on every band change. Without
+// this the per-band default landed in the field FIRST, and the log-time
+// priority (the radio that is keying beats the radio that was planned) never
+// ran — the field was no longer empty by the time the backend looked.
+func (a *App) ActiveRadioMyRig() string {
+	return a.activeRadioMyRig()
+}