[azakai]

> How would a compiler toolchain ship a debugger for webassembly?

You can integrate external debuggers, like Uno documents here:

https://platform.uno/docs/articles/debugging-wasm.html

I assume that uses some browser extension, but I didn't look into the details.

You can also use an extension to provide additional debugging capability in the browser:

https://developer.chrome.com/docs/devtools/wasm