CW was excluded because SmartSDR does not route the operator's own sidetone
through DAX, so the recording sounds one-sided. The audio path is open all the
same and the other station IS captured — which is the half worth keeping.
The frontend had ONE list serving two purposes: which modes may be recorded, and
which modes the voice keyer may transmit on. Adding CW to it would have let the
DVK key the rig with speech on a CW frequency. They are now two lists: PHONE_MODES
for the keyer, RECORDABLE_MODES (phone + CW) for the recorder.
Digital modes stay out of both: their audio is a modem tone nobody will replay.