fix: register onMcpServersChange callback for real-time MCP status updates

The previous implementation manually fetched MCP servers after connect/disconnect,
which returned stale 'disconnected' state since the connection is asynchronous.
SDK's onMcpServersChange callback fires after the connection completes, but was
not registered.

Fix:
- Register onMcpServersChange in ChatSession's AgentCallbacks (wave-agent pattern)
- Forward callback through ChatProvider to webview via 'mcpServersUpdate' message
- ConfigurationDialog now handles both mcpServersResponse (initial) and
  mcpServersUpdate (push) commands
- Remove redundant manual getMcpServers calls in messageHandler
- Update notification message to clarify it indicates request sent, not completion

Author: lewis617

src/chatProvider.ts

@@ -160,6 +160,9 @@ export class ChatProvider implements vscode.WebviewViewProvider {
             },
             onError: (error) => {
                 this.sendErrorToView(error, viewType, windowId);
+            },
+            onMcpServersChange: (servers) => {
+                this.webviewManager.postMessage({ command: 'mcpServersUpdate', servers }, viewType, windowId);
             }
         });
     }

src/session/chatSession.ts

@@ -13,6 +13,7 @@ export interface ChatSessionCallbacks {
     onPermissionModeChange: (mode: PermissionMode) => void;
     onToolPermissionRequest: (context: ToolPermissionContext) => Promise<PermissionDecision>;
     onError: (error: any) => void;
+    onMcpServersChange?: (servers: McpServerStatus[]) => void;
 }
 
 export class ChatSession {
@@ -92,6 +93,9 @@ export class ChatSession {
                 onQueuedMessagesChange: (messages: QueuedMessage[]) => {
                     this.messageQueue = messages;
                     this.callbacks.onQueueChange(messages);
+                },
+                onMcpServersChange: (servers: McpServerStatus[]) => {
+                    this.callbacks.onMcpServersChange?.(servers);
                 }
             };
 

src/session/messageHandler.ts

@@ -714,13 +714,9 @@ export class MessageHandler {
         const session = this.context.getChatSession(viewType || 'tab', windowId);
         try {
             const success = await session.connectMcpServer(serverName);
-            const servers = session.getMcpServers();
-            this.context.postMessage({
-                command: 'mcpServersResponse',
-                servers
-            }, viewType, windowId);
+            // SDK's onMcpServersChange callback will push the updated state to frontend
             if (success) {
-                vscode.window.showInformationMessage(`MCP 服务器 "${serverName}" 已连接`);
+                vscode.window.showInformationMessage(`MCP 服务器 "${serverName}" 连接请求已发送`);
             }
         } catch (error) {
             console.error('连接 MCP 服务器失败:', error);
@@ -732,13 +728,9 @@ export class MessageHandler {
         const session = this.context.getChatSession(viewType || 'tab', windowId);
         try {
             const success = await session.disconnectMcpServer(serverName);
-            const servers = session.getMcpServers();
-            this.context.postMessage({
-                command: 'mcpServersResponse',
-                servers
-            }, viewType, windowId);
+            // SDK's onMcpServersChange callback will push the updated state to frontend
             if (success) {
-                vscode.window.showInformationMessage(`MCP 服务器 "${serverName}" 已断开`);
+                vscode.window.showInformationMessage(`MCP 服务器 "${serverName}" 断开请求已发送`);
             }
         } catch (error) {
             console.error('断开 MCP 服务器失败:', error);

webview/src/components/ConfigurationDialog.tsx

@@ -102,6 +102,11 @@ const ConfigurationDialog: React.FC<ConfigurationDialogProps & { vscode: any }>
           setMcpServers(message.servers || []);
           setMcpConnecting({});
           break;
+        case 'mcpServersUpdate':
+          // Push update from backend (e.g., after connect/disconnect completes)
+          setMcpServers(message.servers || []);
+          setMcpConnecting({});
+          break;
       }
     };
     window.addEventListener('message', handleMessage);