A refactoring in commit 132807a introduced a regression where the final
response was silently discarded whenever the message tool was used,
regardless of the target. This restored the original logic from PR #832
that only suppresses the final reply when the message tool sends to the
same (channel, chat_id) as the original message.
Changes:
- message.py: Replace _sent_in_turn: bool with _turn_sends: list[tuple]
to track actual send targets, add get_turn_sends() method
- loop.py: Check if (msg.channel, msg.chat_id) is in sent_targets before
suppressing final reply. Also move the "Response to" log after the
suppress check to avoid misleading logs.
- Add unit tests for the suppress logic
This ensures:
- Email sent via message tool → Feishu still gets confirmation
- Message tool sends to same Feishu chat → No duplicate (suppressed)
