configure_webmin_2fa used `sed -i ... || echo ... >>` to add
twofactor_provider and twofactor to /etc/webmin/miniserv.conf. sed
returns 0 even when it matches nothing, so when the directives were
absent (the normal case on a fresh Webmin install) the `|| echo` branch
never ran. The script printed "Webmin 2FA configuration completed" while
leaving 2FA entirely unconfigured — caught by 2fa-validation reporting
"Webmin TOTP provider not configured".
Guard each directive with grep so it is appended when absent and updated
when present.
🤖 Generated with [Crush](https://github.com/charmassociates/crush)
Assisted-by: GLM-5 via Crush <crush@charm.land>
mrcharles
65b972e623