try

hosts/fw.cloonar.com/modules/staticids.nix

@@ -5,7 +5,7 @@ let
 in
 {
   
-  options.config.cids = {
+  options.services.cids = {
     uids = mkOption {
       readOnly = true;
       description = lib.mdDoc ''
@@ -23,7 +23,7 @@ in
     };
   };
   config = {
-    cids = {
+    services.cids = {
       uids = {
         unbound = 10001;
       };