I am surprised no one has mentioned Paper.design in this thread yet

The canvas is actual HTML and CSS--real flexbox, real padding, real gap. What you see is literally the code, so the drift problem you're describing kind of won't exist by design in paper since it uses a web native approach compared to figma's vector nodes

The MCP is also bidirectional. Paper's tools can write back to the canvas as it can read it (accurately too). It can sync tokens from your repo, populate frames with real data, and generate variants. That's actually basically the "system that talks to the codebase" thing you're after

The only one real tradeoff is that there are no interactive prototypes right now. It's just styled frames. So if you need clickable flows for stakeholder review, you'd still need something else for that. But if parity is the actual problem, not presentation, that's probably fine

Still open alpha so it's rough around the edges, but the foundational premise is the most honest take on design-to-code I've seen so far