fix(orphan): prevent Claude Code session leaks on macOS

Three bugs were causing orphaned Claude processes to accumulate:

1. TTY comparison in orphan.go checked for "?" but macOS shows "??"
   - Orphan cleanup never found anything on macOS
   - Changed to check for both "?" and "??"

2. selfKillSession in done.go used basic tmux kill-session
   - Claude Code can survive SIGHUP
   - Now uses KillSessionWithProcesses for proper cleanup

3. Crew stop commands used basic KillSession
   - Same issue as #2
   - Updated runCrewRemove, runCrewStop, runCrewStopAll

Root cause of 383 accumulated sessions: every gt done and crew stop
left orphans, and the cleanup never worked on macOS.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

internal/cmd/crew_lifecycle.go

@@ -60,11 +60,11 @@ func runCrewRemove(cmd *cobra.Command, args []string) error {
 			}
 		}
 
-		// Kill session if it exists
+		// Kill session if it exists (with proper process cleanup to avoid orphans)
 		t := tmux.NewTmux()
 		sessionID := crewSessionName(r.Name, name)
 		if hasSession, _ := t.HasSession(sessionID); hasSession {
-			if err := t.KillSession(sessionID); err != nil {
+			if err := t.KillSessionWithProcesses(sessionID); err != nil {
 				fmt.Printf("Error killing session for %s: %v\n", arg, err)
 				lastErr = err
 				continue
@@ -591,8 +591,8 @@ func runCrewStop(cmd *cobra.Command, args []string) error {
 			output, _ = t.CapturePane(sessionID, 50)
 		}
 
-		// Kill the session
+		// Kill the session (with proper process cleanup to avoid orphans)
-		if err := t.KillSession(sessionID); err != nil {
+		if err := t.KillSessionWithProcesses(sessionID); err != nil {
 			fmt.Printf("  %s [%s] %s: %s\n",
 				style.ErrorPrefix,
 				r.Name, name,
@@ -681,8 +681,8 @@ func runCrewStopAll() error {
 			output, _ = t.CapturePane(sessionID, 50)
 		}
 
-		// Kill the session
+		// Kill the session (with proper process cleanup to avoid orphans)
-		if err := t.KillSession(sessionID); err != nil {
+		if err := t.KillSessionWithProcesses(sessionID); err != nil {
 			failed++
 			failures = append(failures, fmt.Sprintf("%s: %v", agentName, err))
 			fmt.Printf("  %s %s\n", style.ErrorPrefix, agentName)

internal/cmd/done.go

@@ -3,7 +3,6 @@ package cmd
 import (
 	"fmt"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"strings"
 
@@ -15,6 +14,7 @@ import (
 	"github.com/steveyegge/gastown/internal/polecat"
 	"github.com/steveyegge/gastown/internal/rig"
 	"github.com/steveyegge/gastown/internal/style"
+	"github.com/steveyegge/gastown/internal/tmux"
 	"github.com/steveyegge/gastown/internal/townlog"
 	"github.com/steveyegge/gastown/internal/workspace"
 )
@@ -743,11 +743,11 @@ func selfKillSession(townRoot string, roleInfo RoleInfo) error {
 	_ = events.LogFeed(events.TypeSessionDeath, agentID,
 		events.SessionDeathPayload(sessionName, agentID, "self-clean: done means gone", "gt done"))
 
-	// Kill our own tmux session
+	// Kill our own tmux session with proper process cleanup
-	// This will terminate Claude and the shell, completing the self-cleaning cycle.
+	// This will terminate Claude and all child processes, completing the self-cleaning cycle.
-	// We use exec.Command instead of the tmux package to avoid import cycles.
+	// We use KillSessionWithProcesses to ensure no orphaned processes are left behind.
-	cmd := exec.Command("tmux", "kill-session", "-t", sessionName) //nolint:gosec // G204: sessionName is derived from env vars, not user input
+	t := tmux.NewTmux()
-	if err := cmd.Run(); err != nil {
+	if err := t.KillSessionWithProcesses(sessionName); err != nil {
 		return fmt.Errorf("killing session %s: %w", sessionName, err)
 	}
 

internal/util/orphan.go

@@ -191,7 +191,8 @@ func FindOrphanedClaudeProcesses() ([]OrphanedProcess, error) {
 		etimeStr := fields[3]
 
 		// Only look for claude/codex processes without a TTY
-		if tty != "?" {
+		// Linux shows "?" for no TTY, macOS shows "??"
+		if tty != "?" && tty != "??" {
 			continue
 		}