Offload functions to worker threads with shared memory primitives for Node.js.

feat: preserve error details across worker boundary master

Errors thrown in moroutines now transfer via structured clone instead of extracting message strings. This preserves stack traces pointing to the actual source, built-in subclass identity (TypeError, RangeError, etc.), and cause chains. Applies to regular dispatch, pool dispatch, and streaming tasks. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>