feat(a2ui): Implement A2UI backend with question handling and WebSocket support

- Added A2UITypes for defining question structures and answers.
- Created A2UIWebSocketHandler for managing WebSocket connections and message handling.
- Developed ask-question tool for interactive user questions via A2UI.
- Introduced platformUtils for platform detection and shell command handling.
- Centralized TypeScript types in index.ts for better organization.
- Implemented compatibility checks for hook templates based on platform requirements.

ccw/frontend/src/pages/index.ts

@@ -17,6 +17,7 @@ export { CommandsManagerPage } from './CommandsManagerPage';
 export { MemoryPage } from './MemoryPage';
 export { SettingsPage } from './SettingsPage';
 export { HelpPage } from './HelpPage';
+export { HookManagerPage } from './HookManagerPage';
 export { NotFoundPage } from './NotFoundPage';
 export { LiteTasksPage } from './LiteTasksPage';
 export { LiteTaskDetailPage } from './LiteTaskDetailPage';
@@ -24,3 +25,8 @@ export { ReviewSessionPage } from './ReviewSessionPage';
 export { McpManagerPage } from './McpManagerPage';
 export { EndpointsPage } from './EndpointsPage';
 export { InstallationsPage } from './InstallationsPage';
+export { ExecutionMonitorPage } from './ExecutionMonitorPage';
+export { RulesManagerPage } from './RulesManagerPage';
+export { PromptHistoryPage } from './PromptHistoryPage';
+export { ExplorerPage } from './ExplorerPage';
+export { GraphExplorerPage } from './GraphExplorerPage';