feat(hostd): varlink interfaced host controller to manage machine configuration and boot mgmt

hostd/src/main.rs

@@ -19,6 +19,7 @@ impl io_patagia_hostd::VarlinkInterface for PatagiaHostd {
     }
 
     fn describe(&self, call: &mut dyn io_patagia_hostd::Call_Describe) -> varlink::Result<()> {
+        // Connect to systemd.Hostname
         let conn =
             varlink::Connection::with_address("unix:/run/systemd/io.systemd.Hostname").unwrap();
         let mut sd = io_systemd_hostname::VarlinkClient::new(conn);