Add RESTART command for master and slaves via ESP-NOW.

UART RESTART (client_id 0 = local reboot, >0 = unicast); dashboard and CLI hooks; delayed esp_restart after response.

Co-authored-by: Cursor <cursoragent@cursor.com>

main/powerpod.c

@@ -3,6 +3,7 @@
 #include "cmd_accel_deadzone.h"
 #include "cmd_espnow_unicast_test.h"
 #include "cmd_espnow_find_me.h"
+#include "cmd_restart.h"
 #include "cmd_client_info.h"
 #include "cmd_version.h"
 #include "cmd_ota.h"
@@ -178,6 +179,7 @@ void app_main(void) {
     cmd_accel_deadzone_register();
     cmd_espnow_unicast_test_register();
     cmd_espnow_find_me_register();
+    cmd_restart_register();
     cmd_led_ring_register();
     cmd_ota_register();
     cmd_ota_slave_progress_register();