Task 4.3: Implement Structured Cloning for Workers

**Phase:** 4 - Risk Mitigation (High Priority)

**Tags:** feature, workers

**Description:**
Refactor `src/workers/workerActor.ts` to use structured cloning for message passing.

**Acceptance Criteria:**
- [ ] Refactor `src/workers/workerActor.ts` to use structured cloning
- [ ] Ensure proper message passing
- [ ] Update tests accordingly