- cmd::group::_output_json: groups array with peer/blocked counts
- cmd::rule::_output_json: rules with extends array, is_base bool fix
- cmd::identity::_output_json: identities with types/rules as arrays
- cmd::net::_output_json: services with tags array and port count
- cmd::activity::_output_json: peers with nested services array
- all commands: command::mixin json_output registered in on_load
