fix: complete README and relevant file headers per Apache 2.0 requirements

tests/unit/utils/test_ui_hierarchy.py

@@ -11,6 +11,9 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+#
+# Portions of this file are derived from mobile-use (https://github.com/minitap-ai/mobile-use)
+# Copyright 2025-2026 Minitap, Inc. Licensed under the Apache License 2.0.
 
 from unittest.mock import patch