feat(cli): 添加 CLI 版本检测和会话验证功能

- 新增 CLI 版本检测功能，支持检测 CLI 版本并缓存结果
- 实现会话验证方法，用于检查当前会话是否有效
- 在连接处理中集成 CLI 版本检测和会话验证逻辑
- 优化 WebViewProvider 中的初始化流程，支持背景初始化
- 更新消息处理逻辑，增加与 CLI 相关的错误处理

packages/vscode-ide-companion/src/webview/hooks/useWebViewMessages.ts

@@ -146,6 +146,41 @@ export const useWebViewMessages = ({
           break;
         }
 
+        // case 'cliNotInstalled': {
+        //   // Show CLI not installed message
+        //   const errorMsg =
+        //     (message?.data?.error as string) ||
+        //     'Qwen Code CLI is not installed. Please install it to enable full functionality.';
+
+        //   handlers.messageHandling.addMessage({
+        //     role: 'assistant',
+        //     content: `Qwen CLI is not installed. Please install it to enable full functionality.\n\nError: ${errorMsg}\n\nInstallation instructions:\n1. Install via npm:\n   npm install -g @qwen-code/qwen-code@latest\n\n2. After installation, reload VS Code or restart the extension.`,
+        //     timestamp: Date.now(),
+        //   });
+        //   break;
+        // }
+
+        // case 'agentConnected': {
+        //   // Agent connected successfully
+        //   handlers.messageHandling.clearWaitingForResponse();
+        //   break;
+        // }
+
+        // case 'agentConnectionError': {
+        //   // Agent connection failed
+        //   handlers.messageHandling.clearWaitingForResponse();
+        //   const errorMsg =
+        //     (message?.data?.message as string) ||
+        //     'Failed to connect to Qwen agent.';
+
+        //   handlers.messageHandling.addMessage({
+        //     role: 'assistant',
+        //     content: `Failed to connect to Qwen agent: ${errorMsg}\nYou can still use the chat UI, but messages won't be sent to AI.`,
+        //     timestamp: Date.now(),
+        //   });
+        //   break;
+        // }
+
         case 'loginError': {
           // Clear loading state and show error notice
           handlers.messageHandling.clearWaitingForResponse();