E2E test infrastructure with Playwright

[jaylfc]

Summary

Set up a Playwright E2E test suite for taOS covering keyboard shortcuts, app navigation, focus management, and the fullscreen launch flow.

Requirements

• Test suite in desktop/tests/e2e/ with playwright.config.ts
• Test helpers: launchApp(), focusWindow(), pressShortcut(), waitForWindow(), getAccessibilityTree()
• Test categories:
  • System shortcuts (Ctrl+1-9, Ctrl+Tab, Ctrl+W, Ctrl+Space, Ctrl+L, Ctrl+Q)
  • Search palette (type-to-search → Enter launches top result)
  • App navigation (Library filter→item→detail→Escape, Settings sections, Store categories)
  • Focus management (modal trap, focus return, window-scoped shortcuts)
  • Fullscreen flow (login → launch → fullscreen → keyboard lock → quit)
• Uses system Chromium on ARM64

Spec

docs/superpowers/specs/2026-04-12-keyboard-nav-fullscreen-design.md — Section 7