eg25-manager: actually ship udev rules (?)

hosts/common/programs/eg25-manager.nix

@@ -4,7 +4,10 @@ let
 in
 {
   sane.programs.eg25-manager = {
+    # it has to be enabled system-wide for its udev rules to make it into /run/current-system/sw/lib/udev/rules.d.
+    enableFor.system = lib.mkIf (builtins.any (en: en) (builtins.attrValues cfg.enableFor.user)) true;
   };
 
+  # not sure if this is required or if it's enough that eg25-manager is on system.packages.
   services.udev.packages = lib.mkIf cfg.enabled [ cfg.package ];
 }