Ahriman
Tyrant
Well, the Tech screenshot still in the video clearly says that workers build Trading Posts unlocked by Trapping. And they increase gold output on the map.
Maybe camps and trading posts are just for different types of resources; camps are for deer and ivory, trading posts for furs and ?
Fur Trading post could be totally unrelated.
Unique improvements would be weird, but not impossible; there's a decent chance the Mughal Fort is a unique improvement. Or it could just be a building in the city.