I think "development" is a telltale too vague category... at least in name. Arguably anything in industry or farming would be "development" as well. I can sort of see a distinction between terraforming and growth/food (though not enough to convince me to split them up). However even if terraforming wasn't with farming/growth, I'm not convined there's any good reason to put it with with trade/commerce/economic stuff. You've suggested a (weak imho) thematic link, but the "development" isn't a sufficiently specific or exclusive relationship between the two subcategories in question to justify their being together.
Agreed that "development" is a bad name. Need a better one.
Here's what the category represents, in my own little head:
roads, space elevators, slaughtering hostile native lifeforms, clearing a forest to make way for a mega-starport, stripmalls, corporate headquarters, damming up a river, irragation, launching a array of mirrors to reflect sunlight away from the planet, thermal boreholes tapping into the core, the power and communications grid, primary schools.
Notice that none of the above directly creates a starship or Wonderous building (Production), a bug-eyed alien baby or a nascent colony (Growth), a grand unification theory or a well-staffed university (Learning), a system of government or a spy agency (Social). It's the stuff of the Construction meter, the Economy meter, and Terraforming.
We "terraform" the planet a little each day, making it more convient to live on by paving roads, irragating dry lands, and sticking dams in front of rivers. In game, a terraforming project would in fact be hundreds of thousands of little projects that culminate in a new enviroment. (all abstracted as a single project in the eyes of the player, of course.)
In short, I don't view Terraforming as a biological process. Sure, a few trees are planted and a few native lifeforms released into the wilds. Maybe some dark algea is planted at the polar ice caps.
Terraforming is gross changes are made to the properties of a world though various means, not just biological. You aren't going to turn a Radiated world into a Terran paradise through biology: you'll need some sort of star trek-ish b.s. super science.
I'm saying Terraforming *can* fit into the construction/trade category. Maybe it could also fit into the Growth category, but it should go into construction anway. Without terraforming the construction category is sparse compared to the others. With terraforming, I believe that all the categories I listed will have about the same number of techs.