feat: add native Windows hierarchy test harness

internal/client/supervisor/windows/testfaults_fixture.go

@@ -0,0 +1,28 @@
+//go:build rvbox_native_test
+
+package windows
+
+import (
+	"fmt"
+	"strings"
+)
+
+// NativeTestContextFailures accepts only the two active elevated preparation
+// stages.  It is compiled into the disposable native-fixture binary, never a
+// release binary, and is applied before a process is launched.
+func NativeTestContextFailures(raw string) (map[ExecutionContext]bool, error) {
+	if raw == "" {
+		return nil, nil
+	}
+	result := make(map[ExecutionContext]bool)
+	for _, item := range strings.Split(raw, ",") {
+		contextName := ExecutionContext(strings.TrimSpace(item))
+		switch contextName {
+		case ContextActiveUserElevated, ContextActiveSystem:
+			result[contextName] = true
+		default:
+			return nil, fmt.Errorf("unsupported native test context %q", item)
+		}
+	}
+	return result, nil
+}