Simplify system prompts for test dialogue in Chinese and English

- Refine prompt content for improved clarity, brevity, and conversational flow.
- Remove redundant "thinking process" elements from both language prompts.

tests/test_llm_dialogue.py

@@ -5,8 +5,6 @@ from pathlib import Path
 from langchain.chains.conversation.memory import ConversationBufferWindowMemory
 from langchain_community.chat_models.llamacpp import ChatLlamaCpp
 from langchain_core.chat_history import InMemoryChatMessageHistory
-from langchain_core.messages import SystemMessage
-from langchain_core.prompts import ChatPromptTemplate, HumanMessagePromptTemplate, MessagesPlaceholder
 from langchain_core.runnables.history import RunnableWithMessageHistory
 
 HERE = Path(__file__).parent.parent
@@ -19,18 +17,17 @@ from voice_dialogue.config.llm_config import get_llm_model_params
 from voice_dialogue.services.text.processor import create_langchain_pipeline
 
 CHINESE_SYSTEM_PROMPT = (
-    "你是善于模拟真实的思考过程的AI助手。"
-    "回答时，必须首先生成一个不超过5个字的简短句子，"
-    "比如：\"让我想一下。\"、\"在我看来。\"、\"稍等我理一理。\"、\"不错的问题。\"、\"稍等片刻。\"等，然后再进行正式回答，"
-    "保持中文口语化表达，禁用emoji和系统相关描述，确保衔接词与内容存在合理逻辑关联。"
+    "你是AI助手。请以自然流畅的中文口语化表达直接回答问题，避免冗余的思考过程。"
+    "你的回答第一句话必须少于十个字。每段回答控制在二到三句话，既不要过短也不要过长，以适应对话语境。"
+    "回答应准确、精炼且有依据。"
     "/no_think"
 )
 
 ENGLISH_SYSTEM_PROMPT = (
-    "You are an AI assistant skilled at simulating authentic thinking processes. "
-    "When responding, you must first generate a brief phrase of no more than 5 words, "
-    "such as: 'Let me think.', 'I see.', 'Let me process this.', 'Good question.', 'One moment.', etc., then proceed with your formal response. "
-    "Maintain natural conversational English expression, avoid emojis and system-related descriptions, and ensure logical coherence between transitional phrases and content."
+    "You are an AI assistant. "
+    "Please answer directly and naturally, using conversational English, without showing your thinking process. "
+    "Your first sentence must be less than 10 words. "
+    "Your responses should be accurate, concise, and well-supported, ideally around 2-3 sentences long to ensure a good conversational flow."
     "/no_think"
 )