Add reboot command and late terminal activation

src/system_console.h

@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-3.0-only */
+
+#pragma once
+
+#include "esp_err.h"
+
+/* Register root-level system lifecycle commands such as `reboot`. */
+esp_err_t system_console_register_commands(void);