[Feature Request] Provide a way to distinguish error types in logs from TypeScript SDK (errors lose type info across Worker <-> Workflow)

[antmendoza]

Is your feature request related to a problem? Please describe.

Currently users cannot distinguish error types in Temporal’s TypeScript SDK logs, all logged errors appear as plain Error objects with no type information. This prevents detecting whether a failure came from an Activity or a Workflow, making it impossible to set appropriate log levels (e.g., log failures as ERROR instead of WARN).

Describe the solution you'd like

I see, it is a documented limitation of NodeJS. Can you guys introduce some indication of type in the field? As I pointed out above (type or code). It will solve the issue. Also, I noticed that failure field is also a string instead of proper object where we can see details. I understand if you change it to an object, it will be a breaking functionality for someone. Maybe we can introduce another one?

Additional context

Slack thread: https://temporalio.slack.com/archives/C01DKSMU94L/p1756795588257069

To be clear, what we’re talking about here are limitations of either Node or V8 themselves, not bugs of the Temporal SDK. See here.