improve handling of copy pasting leading /

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

avoid treating a copy pasted block of text that leads with / as a command

### Proposed solution

If i select `// foo` and copy paste it into the prompt window at the start of the prompt, the CLI attempts to parse this as a command so my prompt fails. Other tools treat pasted text as a block that both that isn't immediately treated as text, this seems like a nice ergonomic win that would address my immediate problem

### Example prompts or workflows

_No response_

### Additional context

_No response_