I installed a smart bulb in my fridge. I plan to set up an automation in Home Assistant to tell me when the fridge has been open too long.

My fridge just beeps at me if the door has been open more than a minute or two.

It's not a 'smart' fridge, either. You don't need anything complex to accomplish that. I guess that the interior fridge light is wired in parallel with a simple timer circuit, and if that timer circuit is energized long enough for its pre-set timer to run out, it energizes the beeping circuit.

You could do a similar thing with your fridge. No need for network connectivity and computers to be involved. Just find the circuit that goes to the light bulb and wire in a simple electronic timer in parallel.