Get gateway, whether it's an IP or hostname

And add v6 versions

lib.nix

@@ -37,9 +37,19 @@ let
     attrNames
     (filterAttrs (_: hostOpts: hostOpts.domain == domain) entities.hosts);
 
-  getSiteGateway = site: entities.sites."${site-name}".gateway-v4;
+  getSiteGatewayV4 = siteName:
+    let site = config.fudo.sites."${siteName}";
+    in if hasAttr "local-gateway" site then getHostIpv4 else site.gateway-v4;
 
-  getHostGateway = hostname: (getHostSite hostname).gateway-v4;
+  getHostGatewayV4 = hostname:
+    getSiteGatewayV4 config.fudo.hosts."${hostname}".site;
+
+  getSiteGatewayV6 = siteName:
+    let site = config.fudo.sites."${siteName}";
+    in if hasAttr "local-gateway" site then getHostIpv6 else site.gateway-v6;
+
+  getHostGatewayV6 = hostname:
+    getSiteGatewayV6 config.fudo.hosts."${hostname}".site;
 
 in {
   inherit getHostSite getHostDomain getHostRealm getHostFqdn getHostIpv4