use agenix

modules/services/grafana.nix

@@ -1,6 +1,7 @@
 { lib, config, ... }:
 let
   cfg = config.modules.services.grafana;
+  secrets = config.age.secrets;
   fqdn = "${cfg.subdomain}.${config.networking.domain}";
 in
 {
@@ -40,7 +41,7 @@ in
           from_address = "noreply@freun.dev";
           from_name = "Vaultwarden";
           user = "noreply@freun.dev";
-          password = "$__file{/var/secrets/smtp-password}";
+          password = "$__file{${secrets.smtp-password.path}}";
         };
       };
     };