nixos/lanraragi: add openFirewall option

Makes it easier to set up the service, many other services offer this option

nixos/modules/services/web-apps/lanraragi.nix

@@ -22,6 +22,10 @@ in
         description = "Port for LANraragi's web interface.";
       };
 
+      openFirewall = lib.mkEnableOption "" // {
+        description = "Open ports in the firewall for the Radarr web interface.";
+      };
+
       passwordFile = lib.mkOption {
         type = lib.types.nullOr lib.types.path;
         default = null;
@@ -103,5 +107,9 @@ in
           EOF
         '';
     };
+
+    networking.firewall = lib.mkIf cfg.openFirewall {
+      allowedTCPPorts = [ cfg.port ];
+    };
   };
 }