fix(feishu): send all messages to topic when in thread

[yorkhellen]

Related Issue

close #3694

Problem

When sending multiple messages (text + files) in a Feishu group topic, only the first message stays in the topic, and subsequent messages get posted directly to the group.

Root Cause

The original code used a first_send flag to only send the first message via reply API, and all subsequent messages via regular send API. However, in topics (identified by thread_id), we should always use reply API to keep all messages in the same topic.

Solution

• Added has_thread_id check: has_thread_id = msg.metadata.get("thread_id")
• Logic:
  • If has_thread_id: All messages use reply API to stay in topic
  • Else if reply_to_message is enabled: Only the first message uses reply API (to avoid duplicate reply bubbles)

Testing

• Added two new test cases:
  • test_send_multiple_messages_all_use_reply_when_in_topic: All messages use reply API when in topic
  • test_send_multiple_messages_only_first_uses_reply_when_reply_to_message: Only first message uses reply when not in topic

[chengyongru]

LGMT

[Re-bin]

Thank you!