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/packages/a2ui-runtime/renderer/components/A2UICard.tsx

@@ -0,0 +1,54 @@
+// ========================================
+// A2UI Card Component Renderer
+// ========================================
+// Maps A2UI Card component to shadcn/ui Card
+
+import React from 'react';
+import { Card, CardHeader, CardTitle, CardDescription, CardContent } from '@/components/ui/Card';
+import type { ComponentRenderer } from '../../core/A2UIComponentRegistry';
+import { resolveTextContent } from '../A2UIRenderer';
+import type { CardComponent } from '../../core/A2UITypes';
+
+interface A2UICardProps {
+  component: CardComponent;
+  state: Record<string, unknown>;
+  onAction: (actionId: string, params: Record<string, unknown>) => void | Promise<void>;
+  resolveBinding: (binding: { path: string }) => unknown;
+}
+
+/**
+ * A2UI Card Component Renderer
+ * Container component with optional title and description
+ */
+export const A2UICard: ComponentRenderer = ({ component, state, onAction, resolveBinding }) => {
+  const cardComp = component as CardComponent;
+  const { Card: cardConfig } = cardComp;
+
+  // Resolve title and description
+  const title = cardConfig.title ? resolveTextContent(cardConfig.title, resolveBinding) : undefined;
+  const description = cardConfig.description ? resolveTextContent(cardConfig.description, resolveBinding) : undefined;
+
+  return (
+    <Card>
+      {(title || description) && (
+        <CardHeader>
+          {title && <CardTitle>{title}</CardTitle>}
+          {description && <CardDescription>{description}</CardDescription>}
+        </CardHeader>
+      )}
+      <CardContent>
+        {cardConfig.content.map((childComp, index) => {
+          // For nested components, we would typically use the registry
+          // But for simplicity in this renderer, we just render a placeholder
+          const childType = Object.keys(childComp)[0];
+          return (
+            <div key={index} data-component-type={childType}>
+              {/* Nested components would be rendered here via A2UIRenderer */}
+              {childType}
+            </div>
+          );
+        })}
+      </CardContent>
+    </Card>
+  );
+};