Bump to v2.1.0: add kao_tui.py developer TUI and WSL venv

- Add kao_tui.py: Textual TUI with Sounds, Faces, Events, Controls tabs
- Add textual to requirements.txt
- Add venv activation instructions to README
- Add Developer TUI section to README

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

requirements.txt

@@ -12,3 +12,4 @@ psutil==7.2.2
 requests==2.32.5
 urllib3==2.6.3
 Werkzeug==3.1.5
+textual