fix: Reference markers in the context may be carried over into the next answer

[leecj]

The answer in the context carries reference markers and passes them to the large model, which may include the markers in the new answer, leading to abnormal reference points.

 {'role': 'assistant', 'content': '设置在地下或半地下空间 ##0$$。'}

What problem does this PR solve?

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Type of change

• Bug Fix (non-breaking change which fixes an issue)