feat(kanidm): add Kanidm service configuration and documentation

systems/jeeves/networking/firewall.nix

@@ -8,6 +8,7 @@ let
     grafana = 3000;
     jellyfin_http = 8096;
     jellyswarrm = 3100;
+    kanidm = 8443;
     nix_binary_cache = 5000;
     ollama = 11434;
     open_webui = 8080;
@@ -28,6 +29,7 @@ in
       ports.gems
       ports.jellyfin_http
       ports.jellyswarrm
+      ports.kanidm
       ports.nix_binary_cache
       ports.share
     ];