Implement hardware factory reset using a button on GPIO7

[Ludovich88]

Device: Altruist URBAN
MCU: ESP32-C6-WROOM-1
GPIO: 7 (input, pulled up to 3.3V when not pressed, shorted to GND when pressed)

Current state:
GPIO7 is unused in the firmware; the button has no effect. There is no way to reset user settings without re-flashing.

Goal:
Add a feature to reset all user settings to factory defaults when the button is pressed during power-on.

Requirements:

1. At power-on, check GPIO7 level:
   • Low (0, button pressed) → perform a software reset to defaults, then restart the device (esp_restart()).
   • High (1, button not pressed) → normal boot.
2. Reset must be reliable: handle contact bounce (add delay, re-read).
3. Reset must erase all non-volatile user data (Wi-Fi credentials, peripheral configuration, etc.).