macOS menu bar accessibility system for Script Kit GPUI. Covers AX-based menu reading,
recursive menu parsing, menu action execution, and SQLite caching. Use when:
(1) Reading application menu bars via Accessibility APIs
(2) Executing menu actions programmatically
(3) Caching menu structures for performance
(4) Working with AXUIElement hierarchy (App -> MenuBar -> MenuBarItem -> Menu -> MenuItem)
(5) Handling keyboard shortcuts and modifier flags