[moetemp]

This PR writes Workflow Records through one Local Activity per call.

What changed?

create_stream, publish and close in a Workflow each run one Local Activity (__temporal_streams_create, __temporal_streams_append, __temporal_streams_close). The plugin registers the three activities.
Writes to one Stream run in order. A failed write raises at the await, or fails the Workflow Task for the _nowait forms. publish returns the last offset.
The run drains its writes before it returns or continues as new, and closes its Streams at the end of the chain.
A write keeps the Workflow Task in its Producer epoch, so a Local Activity retry in the same task dedupes, and a later task withdraws what a failed task wrote. A retry run withdraws the failed run on its first write to each Stream. A create names the run chain as the Stream owner.
The Workflow call buffer, the Activation flush, the durable_writes options and the unused on_workflow_activation_complete plugin hook are gone.
The crate pin moves to s20 f3c74d24, and the sdk-core submodule moves to Brook c6 32ba79d6. Together they drop the Workflow write buffer and the Workflow Task hooks, and add the run's task history to a Local Activity task. The bridge's debug test extension loses its hook counters, and so does tests/worker/test_extension.py.
S110: every Local Activity write (the Workflow writes and a user Local Activity's writer) sends the run's last completed Workflow Task and its failed tasks, from the new activity.Info.workflow_task.previous_started_event_id and failed_tasks. So the run's next write to a Stream withdraws what Local Activities wrote there in tasks that never completed. The Superseded docstring states the limit: a Stream that the run never writes again keeps those Records.

Why?

A Local Activity gives each write a recorded result, so replay does not write again and a write error reaches the caller. The run buffer and its flush on Workflow Task completion are no longer needed.

How did you test it?

New tests cover a write to a closed Stream and to a missing Stream, ordered concurrent publishes with a Replayer that shows no write on replay, a retried append that goes in once, a user Local Activity that runs again after a failed Workflow Task and withdraws its first attempt, and a failed task's Local Activity that the retry task skips, whose Records the next write withdraws. The streams suite passes on the memory and Redis backends, and poe lint is green.

🤖 Generated with Claude Code

[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