[BUG] Windows: CTRL+Z (Undo) Crashed Claude Code

Environment

• Platform (select one):
• [ ] Anthropic API
• [ ] AWS Bedrock
• [ ] Google Vertex AI
• [ x] Other: Windows
• Claude CLI version: 1.0.56
• Operating System: Windows 11

Bug Description

Using the universal Windows key sequence for undoing an action crashed Claude Code.

Steps to Reproduce

1. Paste something you didn't mean to paste into the editor.
2. Hit CTRL+Z
3. Watch Claude Code crash

I expect the last keyboard action to be undone

Actual Behavior

Claude Code has been suspended. Run `fg` to bring Claude Code back.
Note: ctrl + z now suspends Claude Code, ctrl + _ undoes input.
node:internal/process/per_thread:230
        throw new ERR_UNKNOWN_SIGNAL(sig);
        ^

TypeError [ERR_UNKNOWN_SIGNAL]: Unknown signal: SIGSTOP
    at process.kill (node:internal/process/per_thread:230:15)
    at c71.handleSuspend (file:///C:/Users/RobertMcLaws/AppData/Roaming/npm/node_modules/@anthropic-ai/claude-code/cli.js:584:1908)
    at c71.handleInput (file:///C:/Users/RobertMcLaws/AppData/Roaming/npm/node_modules/@anthropic-ai/claude-code/cli.js:584:1159)
    at c71.processInput (file:///C:/Users/RobertMcLaws/AppData/Roaming/npm/node_modules/@anthropic-ai/claude-code/cli.js:584:667)
    at ReadStream.handleReadable (file:///C:/Users/RobertMcLaws/AppData/Roaming/npm/node_modules/@anthropic-ai/claude-code/cli.js:584:1049)
    at ReadStream.emit (node:events:518:28)
    at ReadStream.emit (node:domain:489:12)
    at emitReadable_ (node:internal/streams/readable:834:12)
    at process.processTicksAndRejections (node:internal/process/task_queues:89:21) {
  code: 'ERR_UNKNOWN_SIGNAL'
}

Additional Context

On Windows, there needs to be a different key that suspends the app. CTRL+Z is the universal Windows combination for "Undo".