Well, the network bridging went
horribly wrong - Windows decided to use a common MAC address for all packets forwarded via the bridge, and the Netgear router in turn decided to hand out the same IP address both to Nyx and to the Raspberry Pi.
Neither was particularly impressed by this. Windows at least showed a warning message, but the Pi appeared to just sulk in the corner and not boot.
Anyway, I've changed to Windows' Internet Connection Sharing and that works much better - I can now SSH into the Pi (though I did have to change the Pi's DNS server - it seems that Windows isn't running a resolver). And trawling through the logs shows that it does at least detect the WiFi adapter:
[ 2.603361] usb 1-1.3: new high-speed USB device number 4 using dwc_otg
[ 2.734558] usb 1-1.3: New USB device found, idVendor=2357, idProduct=011e, bcdDevice= 2.00
[ 2.734583] usb 1-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 2.734596] usb 1-1.3: Product: 802.11ac WLAN Adapter
[ 2.734610] usb 1-1.3: Manufacturer: Realtek
[ 2.734622] usb 1-1.3: SerialNumber: 00e04c000001
( More WiFi shenanigans )