feat(briefing): extend post_message() to accept optional metadata dict

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

tests/test_briefing_pipeline.py

@@ -27,3 +27,30 @@ def test_slot_greeting():
     assert "morning" in slot_greeting("compilation").lower() or slot_greeting("compilation")
     assert slot_greeting("morning") != slot_greeting("midday")
     assert slot_greeting("midday") != slot_greeting("afternoon")
+
+
+@pytest.mark.asyncio
+async def test_post_message_accepts_metadata():
+    """post_message should accept an optional metadata dict and store it."""
+    from unittest.mock import AsyncMock, patch, MagicMock
+
+    mock_msg = MagicMock()
+    mock_msg.id = 1
+
+    with patch("fabledassistant.services.briefing_conversations.async_session") as mock_session_cls:
+        mock_session = AsyncMock()
+        mock_session.__aenter__ = AsyncMock(return_value=mock_session)
+        mock_session.__aexit__ = AsyncMock(return_value=False)
+        mock_session.add = MagicMock()
+        mock_session.get = AsyncMock(return_value=None)
+        mock_session.commit = AsyncMock()
+        mock_session.refresh = AsyncMock()
+        mock_session_cls.return_value = mock_session
+
+        from fabledassistant.services.briefing_conversations import post_message
+        metadata = {"weather": {"location": "Berlin"}, "rss_item_ids": [1, 2]}
+        await post_message(1, "assistant", "Hello", metadata=metadata)
+
+        # Verify Message was constructed with msg_metadata
+        call_args = mock_session.add.call_args[0][0]
+        assert call_args.msg_metadata == metadata