"Pending message" doesn't clear on correct timming

### Describe the bug

Found an issue where my Pending message is already consumed and the agent is thinking on it (I can read the thinking) but the message still has "(pending)" appended to it, thus misleading me.

### Affected version

GitHub Copilot CLI 1.0.75.

### Steps to reproduce the behavior

1. Ask tasks that need thinking while on medium or high thinking
2. Add additional prompts while it is still processing (you message is now pending)
3. Check the "Pending message" is appended
4. when the agent start thinking about your message, check the "Pending message" text is still present, although the message has already been delivered.

### Expected behavior

The "pending message" should clear before the agent starts thinking about the message, becaue by now it no longer is pending but was already delivered.

### Additional context

_No response_

Reproduza isso no GitHub Copilot CLI 1.0.75 enviando um prompt enfileirado durante um nível de raciocínio médio ou alto e observe-o quando o agente começar a processar esse prompt. Acompanhe a exibição da mensagem pendente durante a transição de queued para delivered e considere a issue concluída quando o texto “(pending)” desaparecer antes de o agente começar a pensar sobre a mensagem.

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