There are many ways to wire 3 ways, but it sounds like you have the kind where sometimes you flip a switch down to turn the light on, is that right?
In that case, I understand what you were thinking of with the smart bulb, but I still wouldn’t do it that way. Because you run the risk of turning the lights off again if you try to activate the third reality switch.
The challenge that you have is that sometimes when the third reality switch is in the “up“ position the lights are on. But sometimes when the third reality switch is in the “up“ position the lights are off. You can’t change the state of the third reality switch without physically moving the toggle underneath, and that’s not what you want. So the state of the third reality switch is never going to tell you whether the lights are on or off in your case.
Instead, I would just put a light sensor in the garage and when the lux is above a specific level, turn on A virtual switch to act as a proxy. You can do that with the official smart lighting feature.
It’s the virtual switch which will always be on when the lights are on and off when the lights are off. Not the switch on the wall.