bug: TUI - can't tell what I've typed vs agent in scrollback

### Checks

- [x] I have searched [github.com/aws/amazon-q-developer-cli/issues](https://github.com/aws/amazon-q-developer-cli/issues?q=) and there are no duplicates of my issue
- [x] I have run `q doctor` in the affected terminal session
- [x] I have run `q restart` and replicated the issue again

### Operating system

linux

### Expected behaviour

Scroll back, easily find what I've typed vs agent

### Actual behaviour

There is no leading character in scrollback to help me find what I typed vs the agent responded with like the non tui cli

### Steps to reproduce

_No response_

### Environment

```yaml

```