feat(feishu): stream updates on a single card (#1031)

* feat(feishu): stream updates on a single card

* fix(feishu): ensure final message on stream error and warn on missing card ID

- Wrap streaming loop in try/except/finally so a is_final=True outbound
  message is always published, even when the LangGraph stream breaks
  mid-way. This prevents _running_card_ids memory leaks and ensures the
  Feishu card shows a DONE reaction instead of hanging on "Working on it".
- Log a warning when _ensure_running_card gets no message_id back from
  the Feishu reply API, making silent fallback to new-card behavior
  visible in logs.
- Add test_handle_feishu_stream_error_still_sends_final to cover the
  error path.
- Reformat service.py dict comprehension (ruff format, no logic change).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* Avoid blocking inbound on Feishu card creation

---------

Co-authored-by: songyaolun <songyaolun@bytedance.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Co-authored-by: Willem Jiang <willem.jiang@gmail.com>

backend/src/channels/service.py

@@ -33,11 +33,7 @@ class ChannelService:
         langgraph_url = config.pop("langgraph_url", None) or "http://localhost:2024"
         gateway_url = config.pop("gateway_url", None) or "http://localhost:8001"
         default_session = config.pop("session", None)
-        channel_sessions = {
-            name: channel_config.get("session")
-            for name, channel_config in config.items()
-            if isinstance(channel_config, dict)
-        }
+        channel_sessions = {name: channel_config.get("session") for name, channel_config in config.items() if isinstance(channel_config, dict)}
         self.manager = ChannelManager(
             bus=self.bus,
             store=self.store,