Can't login on Windows with passphrase. Imported GPG private key.

I had to do a passphrase reset on my Keybase account because I couldn't remember my passphrase for some reason. After doing the email reset I tried to log in from the CLI using my new passphrase. It said I needed the private key for my public key:

```
Sorry, your account is already established with a PGP public key, but this
utility cannot access the corresponding private key. You need to prove
you're you. We suggest one of the following:

- install GPG and put your PGP private key on this machine and try again
- reset your account and start fresh: https://keybase.io/#account-reset
- go back and provision with another device or paper key
```

After installing GPG and doing `gpg --import keybase-private-key.txt` I validated that the key is listed in `gpg --list-secret-keys`. I'm still getting the same error though.

Is this a bug in the software or am I doing something wrong? I haven't been able to figure it out with the built-in help or online docs.

Reproduce the Windows CLI login flow after importing the private key with `gpg --import keybase-private-key.txt`, then verify the key with `gpg --list-secret-keys`. Review the built-in help and online documentation referenced in the report; the issue is resolved when the imported key is accepted or the required Windows setup is documented.

Written by the indexing model from the issue text.