feat(clan-services): enable recursive services

Using recursive services is potentially complex and requires carefully
designed services. Nested Services create nixos modules which must be
mergable as always.

lib/inventory/distributed-service/tests/default.nix

@@ -278,4 +278,5 @@ in
 
   per_machine_args = import ./per_machine_args.nix { inherit lib callInventoryAdapter; };
   per_instance_args = import ./per_instance_args.nix { inherit lib callInventoryAdapter; };
+  nested = import ./nested_services { inherit lib clanLib; };
 }