With enforce_domain = true, Grafana redirects any request not matching
the configured domain (hosea.shire-zebra.ts.net) back to that hostname.
Since the nginx proxy serves Grafana at grafana.thehellings.lan, every
proxied request gets redirected to the Tailscale address, making the
proxy useless for non-Tailscale clients.
The domain setting is still correct for cookie scoping; enforce_domain
is only needed if direct port access is a concern, which is mitigated
by the firewall (port 3001 is not open on the LAN).
root