Custom serialization for bytes - something instead of a string?

[treykeown]

I think it would be cool to serialize bytes on the Python side, and automatically have that show up as a Uint8Array on the JavaScript side. It should be possible in JS with a custom reviver, but can't I figure out how to control serialization of bytes. I'm trying to get something like this:

b"\xCA\xFE" -> {"__type__": "bytes", "value": "yv4="}

Is it possible to control how bytes are serialized? Seems like the default msgspec behavior is used.