[moetemp]

What changed?

This PR ports the harness's turn-event streams onto temporalio.contrib.streams, the Python face of the temporalio-streams runtime from moetemp/sdk-streams. The agent publishes with workflow_writer, activities append through activity_handle(), and clients and the web app read with get_stream_handle(client, ...). temporalio is pinned to the Bridge top of sdk-python, moe/bridge/v2/dr40-sdk-streams. STREAMS_STORE picks redis (the default, since the web app and the workers are separate processes) or memory. STREAMS_NOTIFY=1 lets idle readers sleep on the server's stream notifier. The first commit is the tree of the closed #2, so the later commits show only the move to the new runtime.

The store now refuses a foreign cursor at the read's first step, not at the call. So attach checks the resume point with a short first read, the Nexus pollMessages answers BAD_REQUEST from inside its read, and a subagent turn falls back to a full replay on the first pull.

Why?

The stream runtime moved out of sdk-python into sdk-streams, and the temporalio.streams registry that #2 used no longer exists. This keeps the harness as the shared yardstick on the current runtime.

How did you test it?

Link to a test plan if any -

• Unit Tests
• Staging
• End to End Tests

[moetemp]

Replaced by #4, which ports the harness onto Brook.