NPC AI CAN see in the dark LOL... I mean if they cannot I have not experienced that darkness allows me to sneak better. Anyway, I tired some experimenting with the motorcycle head light (in various location son various materials) and I see no reason why this game cannot have a flashlight as the head light functions in exactly the same way and THAT is working in the game.
So at the very least this is good news for the possibility for a mod to add a flashlight or head light into the game Fallout 4 style.
I was thinking more how far NPC's can spot you. I used their limited vision range a lot to my advantage, but it wouldn't make sense if they had infrared because you would appear as this glowing object in their vision. Some other issues too.
Cyber flashlight, I think it would work implanted in finger tip, left hand perhaps. I came to think, maybe issue is actually about controls. On Xbox controller at least, how do enable / disable it unless it's separate item, like a weapon? So standard flashlight, that would be then, but then it takes one weapon slot.
Came to think, one of the Gears of Wars games made self conscious joke about that, no flashlights in that universe either.
But in this game, as separate item it's possible and I would take it, despite possible inventory hassle.
Then there's that enemies should react to light, so flashlight would only emit light on certain spectrum visible only via implant player has?