[moetemp]

What changed?

This PR gives StreamRef a pydantic core schema (__get_pydantic_core_schema__). A pydantic model that holds a StreamRef now dumps id, workflowId and firstExecutionRunId, the proto JSON names, as the payload converter already does. It loads both the proto names and snake case. Pydantic is imported only when a model uses the ref, so it stays optional.

Why?

The harness keeps a StreamRef inside a pydantic model, and pydantic wrote it with snake case keys. So the harness had to add its own aliased model.

How did you test it?

pytest tests/contrib/streams/test_pydantic.py. The tests cover:

• model dump and load, in both key forms;
• the pydantic_data_converter payload;
• a Workflow round trip on the memory Store, with pydantic_data_converter and a model that carries the ref.

Full poe lint and the full suite pass at this layer, except test_envconfig, which reads a config file on this host.

• Unit Tests
• Staging
• End to End Tests

[moetemp]

Closing as stale. This layer is folded into the v5 tip, #365, and the upstream review uses a fresh series instead. Plan: https://www.notion.so/4048fc567738814990b7c796ac28fe3f