<i>Note: This is *not* a generic how to setup networking and WiFi on pi question. The IP address is assigned, working and accessible over WiFi in my case</i>.

After configuring a new Raspberry Pi Zero W, I have not been able to ssh into it over WiFi. I get 'connection refused' errors from ssh.

This was still happening after I created the empty file `ssh` in the boot partition (to enable `ssh`), created `wpa_supplicant.conf` in the boot partition (to configure WiFi so it connects to my WiFi router), was able to verify and ping the IP address over Wifi.
 
I read somewhere that the server-side ssh server keys (host keys) can get botched in some Raspian distros.  Unfortunately, the solutions I've seen suggest configuring things from the Raspian desktop, which isn't an option for headless pi. Or using `dpkg` to reconfigure ssh on the Raspian system, but since I can't log in, that's not an option either. 

What can I do?