fix: harden operations and configuration recovery

internal/execsafe/execsafe_test.go

@@ -0,0 +1,31 @@
+package execsafe_test
+
+import (
+	"errors"
+	"os/exec"
+	"path/filepath"
+	"testing"
+
+	"proxyctl/internal/execsafe"
+)
+
+func TestLookPathUsesOnlyTrustedSystemDirectories(t *testing.T) {
+	path, err := execsafe.LookPath("sh")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !filepath.IsAbs(path) || filepath.Base(path) != "sh" {
+		t.Fatalf("resolved path = %q", path)
+	}
+}
+
+func TestLookPathRejectsPathsAndMissingCommands(t *testing.T) {
+	for _, name := range []string{"../systemctl", "/tmp/systemctl", "dir/systemctl", ""} {
+		if _, err := execsafe.LookPath(name); err == nil {
+			t.Fatalf("unsafe name %q was accepted", name)
+		}
+	}
+	if _, err := execsafe.LookPath("proxyctl-command-that-does-not-exist"); !errors.Is(err, exec.ErrNotFound) {
+		t.Fatalf("missing command error = %v", err)
+	}
+}