Most hated keyboard shortcut: CTRL + Z - Copilot CLI says: Goodbye! (green)

### Describe the bug

Every writer, every developer is typing, copying, pasting and undoing and redoing.

First of all copy and paste does NOT work in Copilot. Please refer to other issues.

What happens?
When i select a peace of text outside the CLI, or from another Copilot CLI and right mouse to paste in Copilot CLI (or CTRL +C and CTRL + V), is does NOT work. I paste something old from clipboard, not what i just copied.

Then i use CTRL + Z to undo. This is automatic behavior, 1 millions of people do every day.
I don't want the wrong pasted text. And what happens? Copilot says: Goodbye and exits. I hate this so much!

The only reason i use Copilot CLI is for the auto mode of models and control my models, budgets and policies in github. If Claude CLI or Gemini CLI ever support other models in their future releases then their own, i would switch forever and never use Copilot CLI again. I really hate it.

Please remove the CTRL+Z shortcut or fix it. I lost so many conversations.

ps. On linux it says: please use fq to return to the session. That also doesnt work.

Please fix this very very very anyoing bug!

### Affected version

_No response_

### Steps to reproduce the behavior

_No response_

### Expected behavior

_No response_

### Additional context

_No response_

Start by reproducing the Ctrl+Z exit behavior and the reported copy/paste and `fq` session-return behavior in Copilot CLI, especially on Linux. Inspect the CLI's keyboard shortcut and session input handling; done means Ctrl+Z no longer unexpectedly exits and the documented return-to-session behavior works.

索引モデルが issue の本文から書いたものです。