Feature Request: Idle timeout and possible sleep mode

Hello,

First of all, thank you for such a fun device. I've been using it for a week now, and so far, I'm really enjoying it.

But I've noticed that this device is powered as long as the printer is on; it plays the standby GIF continuously, and this makes the device quite hot to touch in the long term. Considering I live in a quite hot area, I am concerned that this constant heat could negatively affect the device's lifespan and potentially shorten it.

There is a feature to prevent screen burn-in, but it does not help the device cool down at all. So, my suggestion is that when the printer status is at standby for a configurable period (for example, 10 minutes), it should initiate one of the ESP32's sleep modes to turn off the screen and lower power consumption to reduce the heat and protect the device.

As far as I know, the ESP32's deep sleep and light sleep modes are a great way to overcome this problem. It greatly reduces power consumption and disables the pin outputs, so the screen is closed that way (The ESP32 is still connected to the power source; will this cause a problem while in these sleep modes? I don't know.) As a wake-up method, you could set timers so the device will wake up periodically. Another method is to sense a state change from the printer, but I think this is impossible since, in these sleep modes, the Wi-Fi radio is also disabled, and a Wi-Fi connection is needed to communicate with the printer, as far as I know.

There is an another method i found, that is using wifi modem-sleep mod combined with automatic light sleep feature. With this method device is still connected to the wifi. you can check it from [this](https://github.com/espressif/esp-idf/tree/346870a3/examples/wifi/power_save) and [this](https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/system/sleep_modes.html) links.

Thank You!

P.S. To "cool off" the device, i turn off the power of the printer when i am not using it and turn on before i want to print something. Sometimes the devices gives "invalid ip" error after connecting to the Wi-Fi and i have to manually restart the router. i am using the latest firmware so this is another thing i want to report it

No repository files, tests, or entry points are named. Start by reviewing the linked ESP-IDF sleep-mode and Wi-Fi power-save examples, then locate the firmware's standby handling and determine how configurable idle timing and wake-up behavior should work; done means an agreed sleep mode, safe screen shutdown, and reliable recovery when printer activity resumes.

Written by the indexing model from the issue text.