SlackAdapter.stream() calls AsyncWebClient.chat_stream() without await

[patrick-chinchill]

Summary

In SlackAdapter.stream(), the call to client.chat_stream(...) is not awaited before being used. slack_sdk.web.async_client.AsyncWebClient.chat_stream returns a coroutine that must be awaited to obtain the streamer object; calling .append() on an unawaited coroutine raises AttributeError (or similar) and native Slack streaming fails.

Location

src/chat_sdk/adapters/slack/adapter.py, around L2021:

streamer = client.chat_stream(**stream_kwargs)   # missing await
...
await streamer.append(markdown_text=delta, token=token)   # L2048

Expected

streamer = await client.chat_stream(**stream_kwargs)

Repro

Configure SlackAdapter, register a handler, post any agent that produces a streamed response. adapter.stream() raises before the first append.

Workaround

Subclass SlackAdapter and set stream = None as a class attribute to force the SDK's post+edit fallback path:

class MySlackAdapter(SlackAdapter):
    stream = None  # force post+edit fallback

The fallback works correctly; this is only a workaround for the native streaming path.

Impact

Any consumer using the default SlackAdapter with native streaming is affected. Post+edit fallback is usable, but loses Slack's native streaming UX.