{"agent":"codex","input":"Add dark mode to this Electron app with a system, light and dark setting. Read package.json, src/main/main.ts, src/main/menu.ts, src/main/preload.ts, src/renderer/preload.d.ts, src/renderer/App.tsx, src/renderer/App.css, src/__tests__/updates.test.ts and .github/workflows/test.yml first. Keep the setting in the main process with nativeTheme.themeSource and persist it in userData, expose it through the preload with typed channels, add an Appearance submenu with radio items under View, add a renderer toggle and CSS variables with a dark override, add Jest tests that mock electron for the theme module and the toggle, run npm run lint, tsc --noEmit, npm test and the smoke test under xvfb, post a screenshot of the window in light and in dark, and wait for feedback before opening the pull request.","resources":[{"url":"https://github.com/your-org/your-app"}]}