Right click to copy also pastes the content into the input area

### Describe the bug

When I select something and right click to copy, the right click also pastes what was copied into the prompt input. What gets pasted may not even be what was selected, it can also be the previous thing that was selected.

### Affected version

GitHub Copilot CLI 1.0.71-1

### Steps to reproduce the behavior

1. Highlight text in the terminal
2. Right click to copy
3. Observe terminal now contains information that was not meant to be pasted

### Expected behavior

When I right click to copy, nothing should get pasted at the same time.

### Additional context

_No response_

Start by reproducing this in GitHub Copilot CLI 1.0.71-1: highlight terminal text and right-click to copy. Trace the terminal input and paste handling, then verify that right-click copying no longer inserts selected or previously selected content into the prompt input.

Written by the indexing model from the issue text.