fix: clear workspace project PR CI failures

backend/internal/ports/outbound.go

@@ -213,6 +213,8 @@ type WorkspaceProjectConfig struct {
 	Repos         []WorkspaceProjectRepoConfig
 }
 
+// WorkspaceProjectRepoConfig describes one registered child repo in a
+// workspace project session.
 type WorkspaceProjectRepoConfig struct {
 	Name         string
 	RelativePath string
@@ -227,6 +229,8 @@ type WorkspaceProjectInfo struct {
 	Worktrees []WorkspaceRepoInfo
 }
 
+// WorkspaceRepoInfo describes one materialized repo worktree in a workspace
+// project session.
 type WorkspaceRepoInfo struct {
 	RepoName     string
 	RepoPath     string

backend/internal/processalive/process_unix.go

@@ -5,16 +5,32 @@
 package processalive
 
 import (
+	"bytes"
 	"errors"
+	"os/exec"
+	"strconv"
 	"syscall"
 )
 
-// Alive reports whether pid exists. EPERM counts as alive: the process exists
-// even if the current user cannot signal it.
+// Alive reports whether pid maps to a running process. EPERM counts as alive:
+// the process exists even if the current user cannot signal it. Zombies are
+// treated as not alive because the executable has already exited; only its
+// parent has not reaped the process table entry yet.
 func Alive(pid int) bool {
 	if pid <= 0 {
 		return false
 	}
 	err := syscall.Kill(pid, 0)
-	return err == nil || errors.Is(err, syscall.EPERM)
+	if err != nil && !errors.Is(err, syscall.EPERM) {
+		return false
+	}
+	return !isZombie(pid)
+}
+
+func isZombie(pid int) bool {
+	out, err := exec.Command("ps", "-o", "stat=", "-p", strconv.Itoa(pid)).Output()
+	if err != nil {
+		return false
+	}
+	return bytes.HasPrefix(bytes.TrimSpace(out), []byte("Z"))
 }

backend/internal/processalive/process_unix_test.go

@@ -0,0 +1,29 @@
+//go:build !windows
+
+package processalive
+
+import (
+	"os/exec"
+	"testing"
+	"time"
+)
+
+func TestAliveReportsZombieAsDead(t *testing.T) {
+	cmd := exec.Command("sh", "-c", "exit 0")
+	if err := cmd.Start(); err != nil {
+		t.Fatalf("start child: %v", err)
+	}
+	defer func() { _ = cmd.Wait() }()
+
+	deadline := time.Now().Add(5 * time.Second)
+	for time.Now().Before(deadline) {
+		if isZombie(cmd.Process.Pid) {
+			if Alive(cmd.Process.Pid) {
+				t.Fatal("Alive returned true for zombie process")
+			}
+			return
+		}
+		time.Sleep(10 * time.Millisecond)
+	}
+	t.Fatal("child did not become a zombie before timeout")
+}