I ultimately ended up in the SSH shell and tried the following to enable the wlan0 adapter:
sudo ifconfig wlan0 up
ifconfig: SIOCSIFFLAGS: Operation not possible due to RF-kill
I don't understand why this was set. In any case, once I got here, the issue was trivial to resolve.
sudo rfkill list # to see what's going on
sudo rfkill unblock wifi; sudo rfkill unblock all
sudo rfkill list # confirm that the change worked
Followed by a reboot.