Woah that's awesome. Using Effect to represent mutations is brilliant!
Any chance your project is public? I'd love to dig into the details. Alternatively would you be willing to nerd out on this over a call sometime? You can reach me at hello [at] orbitinghail [dotdev]
As promised, here's the code. I decided to call it Synchrotron. Not ready for use yet but there is design/planning in the readme and a suite of passing tests showing that the approach can work. https://github.com/evelant/synchrotron
I haven't put it up in a github repo yet, it's not finished enough, but I will after spending a little more time hacking on it. I'll try to remember to come back here to comment when I do =)
Using effect really doesn't introduce anything special -- plain async typescript functions would work fine too. My approach is certainly a lot less sophisticated than yours with Graft or SQLSync! I just like using Effect. It makes working with typescript a lot more pleasant.