Allow copilot to see the output from user shell commands

### Describe the feature or problem you'd like to solve

Sometimes I want to run commands myself and have copilot see the command and the output. It doesn't see it right now

### Proposed solution

If I could use copilot cli as my terminal, and allow copilot to see what my workflow is and the context I have, copilot could learn my workflow and become much more efficient. I often have two terminals, one for copilot, one for my own commands, and find myself executing commands in my own terminal to make it easier for myself.

I think Warp does this really well, and there I don't even need to prefix `!`, it has some way of knowing what's a command and what's a prompt. I would love a "Terminal mode" like that, but allowing copilot to see the command would be a great start.

### Example prompts or workflows

Arguments to commands that are not in any skills or in documentation.
Following one-off workflows that don't warrant a full skill.
Creating new skills for frequent workflows.
Copilot can learn my workflow, store memories, and work how I work.

### Additional context

_No response_