refactor: clean up legacy code, rename hopper to entity_extractor, and add third-party notices

- Add NOTICE file and README license references for mobile-use and finalrun-agent
- Add derivative attribution headers to 17 files derived from mobile-use
- Rename hopper agent to entity_extractor across prompts, tools, and configs
- Remove obsolete adb_tunnel, ApiBaseUrl, and legacy CLI utility scripts
- Replace legacy examples with native Artemis diagnostic and workflow examples
- Update unit and tool tests to validate entity_extractor and SDK builders

tests/tools/entity_extractor/test_entity_extractor_tools.py

@@ -14,6 +14,6 @@
 
 """This file is intentionally empty.
 
-The hopper agent does not expose any tools directly. It is invoked
+The entity_extractor agent does not expose any tools directly. It is invoked
 programmatically by other tools (e.g., launch_app_tool) as an LLM utility.
 """