Merge PowerSaving-v18 into keymindCascade

Integrate the ESP32 power-saving core and RXPS recovery/status updates while preserving radio2, telemetry and saved settings.

examples/simple_sensor/main.cpp

@@ -475,4 +475,8 @@ void loop() {
     delay(1); // Keep USB and the button wake interval serviced while idle.
   }
 #endif
+  if (the_mesh.getNodePrefs()->reboot_interval > 0 &&
+      the_mesh.millisHasNowPassed(the_mesh.getNodePrefs()->reboot_interval * 3600000UL)) {
+    board.reboot();
+  }
 }