Regenerated for the native stream protos.

[moetemp]

This PR regenerates the Go code for native server streams.

What changed?

• proto/api moves to the native stream commit on the moetemp/api fork.
• Everything else is what the pin forces: StreamSlice, StreamRange and StreamStartPosition, the two stream commands and events, stream_slices on the poll response, consumed_stream_ranges on the completed event, the enum values, and temporalproto/openapi.
• The payload visitor now reaches records through AppendStreamRecordsCommandAttributes.records and PollWorkflowTaskQueueResponse.stream_slices, so a codec sees record bodies and metadata both ways.
• proxy/interceptor_test.go is the one hand edit. Each record on the append command adds two payload sites, its body and its metadata values, so the expected counts for Command and RespondWorkflowTaskCompletedRequest go up by two.

Part of AI-198 (epic AI-37).

Why?

It's the Go half of the native stream api PR, and it's the module version the server's stream PRs pin. The test edit is there because the visitor walks new payloads, and that's the point.

How did you test it?

Link to a test plan if any -

• Unit Tests
• Staging
• End to End Tests

Same generator run and plugin versions as the channel PRs. make check, go build ./... and go test -tags protolegacy ./... pass, the visitor test included. go vet passes everywhere except internal/protojson, which fails the same way on main.

[moetemp]

Paused per the 2026-10-05 design review (the decision record is on the proposal page, section 14). Resumes in phase 2 with the CHASM notification work. The branch stays as a pin.