Regenerated for the workflow listener protos.

[moetemp]

This PR regenerates the Go code for the workflow listener of a notification channel.

What changed?

• proto/api moves to the workflow listener commit on the moetemp/api fork.
• Everything else is what the pin forces: the two commands and events, notifications on the scheduled event, channel_subscriptions on describe, the enum values, and temporalproto/openapi.
• The payload visitor walks the notifications on WorkflowTaskScheduledEventAttributes and the held one on ChannelSubscriptionInfo, so a codec reaches their metadata in History and on describe.

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

Why?

It's the Go half of the workflow listener api PR, and it's the module version the server pins. Nothing here is hand-written.

How did you test it?

Link to a test plan if any -

• Unit Tests
• Staging
• End to End Tests

Same generator run as the previous PR. make check, go build ./... and go test -tags protolegacy ./... pass. The interceptor test needs no payload-count change because the channel commands carry no payload. 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.