CLI pauses execution when terminal/composer loses focus

Description

Claude Code CLI freezes execution when the cursor leaves the composer input area or the terminal window loses focus. The AI stops processing tool calls, writing code, and producing output until focus returns to the composer.

Reproduction

1. Start a multi-step task (e.g., editing multiple files, running tests)
2. While Claude is working, switch to another application (browser, another terminal, Finder)
3. Claude's output freezes mid-execution
4. Switch back to the Claude Code terminal
5. Execution resumes immediately

Expected Behavior

Claude Code should continue executing autonomously regardless of terminal focus state. The user is paying for compute time — pausing execution because the terminal isn't focused wastes that time and breaks autonomous workflows.

Impact

• Breaks autonomous agent workflows where the human multitasks while AI works
• Breaks /loop and background monitoring patterns that are designed to run unattended
• Forces the user to babysit the terminal instead of doing other work
• Effectively steals paid compute time by silently pausing

Environment

• macOS (Darwin 25.4.0)
• Claude Code 2.1.117
• Terminal: default macOS Terminal and iTerm2
• Subscription: Max

Context

This is particularly problematic for users building autonomous agent infrastructure where Claude Code needs to execute long-running tasks, scheduled jobs, and multi-slice development workflows without human supervision.