[fix] Problems with overlapping specific turns when generating LLM final answers

[SeongBeomLEE]

There is an issue in the metaSearchAgent.ts code where the user turn is duplicated when the following code executes. This can be critical when the user's input is long.

      ChatPromptTemplate.fromMessages([
        ['system', this.config.responsePrompt],
        new MessagesPlaceholder('chat_history'),
        ['user', '{query}'],
      ]),

Additionally, in the ChatWindow.tsx code, there is an issue where the rewrite function continues to use the past ChatHistory as is. Since LLMs tend to generate similar responses when the same user input appears in previous turns, this can negatively impact the performance of the rewrite function.

To resolve these issues, I modified the part in the sendMessage function where the history and user turn are combined, and I also updated the rewrite logic to use useEffect.

Thanks.