I've always liked the ggplot2 and the Grammar of Graphics approach to plotting so much so that I wrote my own DSL based on it - it is standalone, written in Rust, has WASM bindings (as you can see on the website) and more:

https://williamcotton.github.io/algraf

It pairs well with a related data translation DSL:

https://williamcotton.github.io/pdl

And you can see the two working together here:

https://williamcotton.github.io/datafarm-studio

There's LSPs for both, LSP clients for VS Code, and even language diagnostics for standalone Monaco editors in the browser.

Of note is that the same language diagnostics are exposed via the WASM as via the LSP interface allowing for the same friendly red squiggles to look and work the same in both your browser with Monaco and your editor with the LSP!