Middle-click paste (X11 primary selection) broken since v1.0.11

## Description

Middle-click paste (X11 primary selection) stopped working in the Copilot CLI chat prompt starting in v1.0.11. It works correctly in v1.0.3.

## Environment

- **OS:** SUSE Linux (kernel 5.14.21)
- **Terminal:** SSH session with X11 forwarding, TERM=xterm-color
- **Display:** X.Org X11
- **Works in:** v1.0.3
- **Broken in:** v1.0.11

## Steps to Reproduce

1. Connect via SSH with X11 forwarding
2. Launch Copilot CLI v1.0.11
3. Copy some text (select with mouse to populate X11 primary selection)
4. Middle-click in the chat prompt to paste
5. **Result:** Paste does not occur — the mouse event is captured by the app
6. **Expected:** Text should be pasted, as it does in v1.0.3

## Notes

- Shift+Middle-click works as a workaround (bypasses app mouse capture)
- Both versions tested in identical SSH sessions to the same machine, same terminal emulator, same TERM value, same X display
- The regression appears to be caused by a change in how mouse reporting/capture is handled between v1.0.3 and v1.0.11
- Sending escape sequences to disable mouse reporting (\e[?1000l etc.) from within the CLI does not help, as the app re-enables mouse capture on each prompt

## Workaround

Use Shift+Middle-click, or downgrade to v1.0.3.