♻️ refactor: implement Phase 1 folder-pattern compliance

- Rename App.tsx to app.tsx (kebab-case naming convention)
- Add barrel exports (index.ts) for src/hooks/
- Add barrel exports (index.ts) for src/components/dialogs/
- Add barrel exports (index.ts) for src/components/layout/
- Update renderer.tsx import to use lowercase app.tsx

This is Phase 1 of folder-pattern.md compliance: establishing proper
file naming conventions and barrel export patterns.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

apps/ui/src/hooks/index.ts

@@ -0,0 +1,9 @@
+export { useAutoMode } from './use-auto-mode';
+export { useBoardBackgroundSettings } from './use-board-background-settings';
+export { useElectronAgent } from './use-electron-agent';
+export { useKeyboardShortcuts } from './use-keyboard-shortcuts';
+export { useMessageQueue } from './use-message-queue';
+export { useResponsiveKanban } from './use-responsive-kanban';
+export { useScrollTracking } from './use-scroll-tracking';
+export { useSettingsMigration } from './use-settings-migration';
+export { useWindowState } from './use-window-state';