feat: manage task process lifetimes and preserve turn history

internal/processguard/check.go

@@ -0,0 +1,52 @@
+package processguard
+
+import (
+	"context"
+	"crypto/rand"
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+)
+
+// Check exercises the real creation path, including clone3/Job inheritance,
+// watchdog readiness, admission and cleanup. It does not start the HTTP server.
+func Check(ctx context.Context) (backend string, err error) {
+	var id [16]byte
+	if _, err = rand.Read(id[:]); err != nil {
+		return "", err
+	}
+	name := fmt.Sprintf("%x-%x-%x-%x-%x", id[:4], id[4:6], id[6:8], id[8:10], id[10:])
+	g, err := New(name)
+	if err != nil {
+		return "", err
+	}
+	defer func() { err = errors.Join(err, g.Close(ctx)) }()
+	exe, err := os.Executable()
+	if err != nil {
+		return "", err
+	}
+	cmd := exec.CommandContext(ctx, exe, "-h")
+	configureGuardian(cmd)
+	launch, err := g.Prepare(cmd)
+	if err != nil {
+		return "", err
+	}
+	defer launch.Dispose()
+	if err = cmd.Start(); err != nil {
+		return "", err
+	}
+	if err = launch.Commit(); err != nil {
+		_ = cmd.Process.Kill()
+		_ = cmd.Wait()
+		return "", err
+	}
+	err = cmd.Wait()
+	if err != nil {
+		return "", err
+	}
+	if err = g.Release(cmd.Process.Pid); err != nil {
+		return "", err
+	}
+	return g.Name(), nil
+}