[BUG] Orphaned Claude Code processes accumulate - 5 processes using 1.4GB when only 1 session expected

Environment

• Claude Code version: 2.1.15
• OS: macOS 26.2 (Tahoe)
• Architecture: arm64 (Apple Silicon)
• Total RAM: 8GB

Description

Multiple orphaned Claude Code processes persist after sessions are closed, accumulating memory. User expected 1 active session but found 5 Claude processes consuming ~1.4GB combined.

Reproduction

1. Use Claude Code normally over a workday
2. Close sessions via terminal exit or Ctrl+C
3. Check running processes: ps aux | awk '/[c]laude$/ {print}'
4. Observe orphaned processes still consuming memory

Evidence

PID: 10360 | RSS: 396MB | %MEM: 4.8 | Started: 8:52AM   <- Current session
PID: 59073 | RSS: 372MB | %MEM: 4.5 | Started: 11:35AM  <- Orphaned
PID: 58877 | RSS: 286MB | %MEM: 3.5 | Started: 11:34AM  <- Orphaned
PID: 87073 | RSS: 154MB | %MEM: 1.9 | Started: 4:39PM   <- Orphaned
PID: 9897  | RSS: 148MB | %MEM: 1.8 | Started: 8:51AM   <- Orphaned

Total orphaned processes: 4
Total orphaned memory: ~960MB
System memory state: 7535MB used / 8GB total (94%), only 80MB free

System Impact

• System nearly out of memory (80MB free)
• Heavy swap usage (compressor storing 19GB+)
• Performance degradation

Related Issues

This appears related to:

• #16508 - Closed session tabs don't release processes
• #18859 - Memory leak in idle sessions

Expected Behavior

When a Claude Code session is closed (terminal exit, Ctrl+C, or tab close), the process should fully terminate and release all memory.

Actual Behavior

Processes persist indefinitely, accumulating memory. Only a full system restart or manual kill clears them.

Workaround

# Kill all orphaned Claude processes except current
ps aux | awk '/[c]laude$/ {print $2}' | xargs kill -9