feat(monitoring): add Portal-1 and Vultr dashboards

- scrape Portal-1 node metrics over Tailscale
- add a hardened Vultr billing and bandwidth exporter
- provision host health and infrastructure cost dashboards

systems/jeeves/monitoring/default.nix

@@ -43,8 +43,15 @@ let
         static_configs = [
           (mkTarget "jeeves" "jeeves.taile39c31.ts.net:9100")
           (mkTarget "bob" "bob.taile39c31.ts.net:9100")
+          (mkTarget "portal-1" "portal-1.taile39c31.ts.net:9100")
         ];
       }
+      {
+        job_name = "vultr";
+        scrape_interval = "5m";
+        scrape_timeout = "45s";
+        static_configs = [ (mkTarget "vultr" "127.0.0.1:9188") ];
+      }
       {
         job_name = "process_grouped";
         static_configs = [
@@ -153,6 +160,8 @@ let
     };
 in
 {
+  imports = [ ./vultr-exporter.nix ];
+
   users = {
     groups.prometheus = { };
     users.prometheus = {