Orphaned Claude processes not cleaned up - high CPU usage

Description

Orphaned Claude CLI processes are not being cleaned up and continue to consume significant CPU resources for extended periods (days/weeks).

Environment

• macOS (Darwin 25.2.0)
• Claude Code CLI

Observed Behavior

Found multiple orphaned claude processes consuming high CPU:

| PID | CPU Usage | Started | Runtime |
|-----|-----------|---------|---------|
| 38206 | 197.9% | Jan 25 | ~1 week |
| 68220 | 111.5% | Monday | 6319+ minutes |

These processes appear to be from previous CLI sessions that were not properly terminated or cleaned up.

Expected Behavior

Claude should:

1. Detect and clean up orphaned processes from previous sessions on startup
2. Properly terminate child processes when a session ends
3. Implement a heartbeat/watchdog mechanism to prevent zombie processes

Impact

• High CPU usage affecting system performance
• Users may not notice until system becomes slow
• Manual intervention required to kill orphaned processes

Steps to Reproduce

1. Use Claude CLI over multiple sessions
2. Sessions may be interrupted or terminals closed
3. Over time, orphaned processes accumulate

Suggested Fix

Consider implementing:

• Process group management for proper cleanup
• Startup check for stale processes from previous sessions
• Watchdog/heartbeat mechanism
• Graceful shutdown handlers for SIGTERM/SIGHUP