A "GPIO discover" mode to toggle/probe GPIO to found who is connected where

**Describe the problem you have/What new integration you would like**

For a new device I have to open-it, follow trace on PCB to guess the GPIO number to control a relay, a LED or button. I don't want to open device, I hope there is a way to control each GPIO via console command to see who is connected to a relay, who is getting the state of a button etc.

**Please describe your use case for this integration and alternatives you've tried:**

Tuya or SmartLife aren't easy to open, there is many version of the same looking smartplug (for example) but one use the GPIO2 for the relay, the other use GPIO 13 etc. Right now I'm making a template with switches for all GPIO and toggle them one by one to identify what I need (relay, LED, etc.), then for button I making the same to see where is connected my buttons.

**Additional context**

It wouldn't help for complexe device using bus like SPI or I²C but for ON/OFF GPIO or even PWM GPIO based device it's a good start.

The request names no files, tests, or entry points. Start by locating the existing GPIO configuration and console or diagnostic interfaces, then define how discovery should probe GPIO and what output would identify connected relays, LEDs, buttons, or PWM devices.

Written by the indexing model from the issue text.