Trellis.cpp now has a studio!

When Trellis.cpp released, people were rightly complaining that while the port was nice, the usability barrier was still high since you had to navigate the command line and fetch all the weights manually. So now, Trellis.cpp has a built-in simple Studio binary: picks the proper backend for you, downloads the weights and allows image-to-3D generation with a Three.js preview component when you can look at the assets you've created.