Unable to select multiple response lines and copy response text when Copilot CLI is moved to a new window in VS Code

### Describe the bug

In VS Code on Mac, when I move GHCP CLI to a new window, I'm
- Unable to select multiple lines of response text either through mouse or mac track pad (3-finger drag and select)
- Copy keyboard shortcut doesn't work when a single line is selected through double clicking
- When a single line is selected through double clicking, right click mouse to copy deselects the line and instead, it selects the word where the mouse is at.

### Affected version

GitHub Copilot CLI 1.0.57-3

VS Code:
Version: 1.122.1 (Universal)
Commit: 8761a5560cfd65fdd19ce7e2bd18dab5c0a4d84e
Date: 2026-05-29T09:25:37+02:00
Electron: 39.8.8
ElectronBuildId: 13870025
Chromium: 142.0.7444.265
Node.js: 22.22.1
V8: 14.2.231.22-electron.0
OS: Darwin arm64 24.6.0

### Steps to reproduce the behavior

- Start GHCP CLI in Terminal
- Move it into a new window
- Type anything to trigger a multi-line response
- Select multiple response lines with mouse or mac trackpad with 3-finger drag-n-select gesture. Notice it won't be able to select
- Double click on a response line to select the whole line. Use Command + C to copy. Notice nothing is copied out.
- Double click on a response line to select the whole line. Use mouse right click to copy. Notice the line gets deselected, and the word where the mouse is at gets selected instead

### Expected behavior

Copy paste works fine when GHCP CLI is not in a new window. Copy paste should also work when it's in a new window

### Additional context

_No response_

Reproduce the selection and copy failures by starting GHCP CLI in Terminal, moving it to a new VS Code window, and triggering a multiline response. Trace the new-window handling and text-selection entry points from there; done means mouse, trackpad, Command+C, and context-menu copying work as they do before the move.

Written by the indexing model from the issue text.