monitoring02: add Caddy reverse proxy for VictoriaMetrics and vmalert

Add metrics.home.2rjus.net and vmalert.home.2rjus.net CNAMEs with
Caddy TLS termination via internal ACME CA.

Refactors Grafana's Caddy config from configFile to globalConfig +
virtualHosts so both modules can contribute routes to the same
Caddy instance.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

services/victoriametrics/default.nix

@@ -183,6 +183,14 @@ in
     };
   };
 
+  # Caddy reverse proxy for VictoriaMetrics and vmalert
+  services.caddy.virtualHosts."metrics.home.2rjus.net".extraConfig = ''
+    reverse_proxy http://127.0.0.1:8428
+  '';
+  services.caddy.virtualHosts."vmalert.home.2rjus.net".extraConfig = ''
+    reverse_proxy http://127.0.0.1:8880
+  '';
+
   # Alertmanager - same config as monitoring01 but will only receive
   # alerts after cutover (vmalert notifier is disabled above)
   services.prometheus.alertmanager = {