feat(workflow): support TypeInfo for workflow transitions

[THardy98]

What was changed

Propagated TypeInfo through child Workflow inputs and results and through continue-as-new inputs. Child Workflow functions use definition metadata, string Workflow types can supply call-site metadata, and same-type continue-as-new reuses the current Workflow input metadata.

This is PR 4 and the final layer of the stack; it depends on #2252.

Why?

Typed client start and result paths do not cover serialization boundaries created inside a Workflow. Without this layer, child calls and continued runs fall back to untyped payload conversion.

Continue-as-new accepts input metadata only because the client handle retains the original Workflow result contract across the run chain. Existing Workflows are unchanged; no rollout or manual steps are required.

Checklist

1. Closes: N/A

2. How was this tested: Common, Client, Worker, Workflow, and test package builds; ESLint; Prettier; 10 focused unit tests; 4 workflow tests; and all 13 mapper-only JSON integration scenarios.

3. Any docs updates needed? No; documentation will accompany the completed experimental API.