feat: implement SDK MCP server support and enhance control request handling

- Added new `SdkMcpController` to manage communication between CLI MCP clients and SDK MCP servers.
- Introduced `createSdkMcpServer` function for creating SDK-embedded MCP servers.
- Updated configuration options to support both external and SDK MCP servers.
- Enhanced timeout settings for various SDK operations, including MCP requests.
- Refactored existing control request handling to accommodate new SDK MCP server functionality.
- Updated tests to cover new SDK MCP server features and ensure proper integration.

packages/core/src/tools/sdk-control-client-transport.ts

@@ -0,0 +1,163 @@
+/**
+ * @license
+ * Copyright 2025 Qwen Team
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * SdkControlClientTransport - MCP Client transport for SDK MCP servers
+ *
+ * This transport enables CLI's MCP client to connect to SDK MCP servers
+ * through the control plane. Messages are routed:
+ *
+ * CLI MCP Client → SdkControlClientTransport → sendMcpMessage() →
+ * control_request (mcp_message) → SDK → control_response → onmessage → CLI
+ *
+ * Unlike StdioClientTransport which spawns a subprocess, this transport
+ * communicates with SDK MCP servers running in the SDK process.
+ */
+
+import type { JSONRPCMessage } from '@modelcontextprotocol/sdk/types.js';
+
+/**
+ * Callback to send MCP messages to SDK via control plane
+ * Returns the MCP response from the SDK
+ */
+export type SendMcpMessageCallback = (
+  serverName: string,
+  message: JSONRPCMessage,
+) => Promise<JSONRPCMessage>;
+
+export interface SdkControlClientTransportOptions {
+  serverName: string;
+  sendMcpMessage: SendMcpMessageCallback;
+  debugMode?: boolean;
+}
+
+/**
+ * MCP Client Transport for SDK MCP servers
+ *
+ * Implements the @modelcontextprotocol/sdk Transport interface to enable
+ * CLI's MCP client to connect to SDK MCP servers via the control plane.
+ */
+export class SdkControlClientTransport {
+  private serverName: string;
+  private sendMcpMessage: SendMcpMessageCallback;
+  private debugMode: boolean;
+  private started = false;
+
+  // Transport interface callbacks
+  onmessage?: (message: JSONRPCMessage) => void;
+  onerror?: (error: Error) => void;
+  onclose?: () => void;
+
+  constructor(options: SdkControlClientTransportOptions) {
+    this.serverName = options.serverName;
+    this.sendMcpMessage = options.sendMcpMessage;
+    this.debugMode = options.debugMode ?? false;
+  }
+
+  /**
+   * Start the transport
+   * For SDK transport, this just marks it as ready - no subprocess to spawn
+   */
+  async start(): Promise<void> {
+    if (this.started) {
+      return;
+    }
+
+    this.started = true;
+
+    if (this.debugMode) {
+      console.error(
+        `[SdkControlClientTransport] Started for server '${this.serverName}'`,
+      );
+    }
+  }
+
+  /**
+   * Send a message to the SDK MCP server via control plane
+   *
+   * Routes the message through the control plane and delivers
+   * the response via onmessage callback.
+   */
+  async send(message: JSONRPCMessage): Promise<void> {
+    if (!this.started) {
+      throw new Error(
+        `SdkControlClientTransport (${this.serverName}) not started. Call start() first.`,
+      );
+    }
+
+    if (this.debugMode) {
+      console.error(
+        `[SdkControlClientTransport] Sending message to '${this.serverName}':`,
+        JSON.stringify(message),
+      );
+    }
+
+    try {
+      // Send message to SDK and wait for response
+      const response = await this.sendMcpMessage(this.serverName, message);
+
+      if (this.debugMode) {
+        console.error(
+          `[SdkControlClientTransport] Received response from '${this.serverName}':`,
+          JSON.stringify(response),
+        );
+      }
+
+      // Deliver response via onmessage callback
+      if (this.onmessage) {
+        this.onmessage(response);
+      }
+    } catch (error) {
+      if (this.debugMode) {
+        console.error(
+          `[SdkControlClientTransport] Error sending to '${this.serverName}':`,
+          error,
+        );
+      }
+
+      if (this.onerror) {
+        this.onerror(error instanceof Error ? error : new Error(String(error)));
+      }
+
+      throw error;
+    }
+  }
+
+  /**
+   * Close the transport
+   */
+  async close(): Promise<void> {
+    if (!this.started) {
+      return;
+    }
+
+    this.started = false;
+
+    if (this.debugMode) {
+      console.error(
+        `[SdkControlClientTransport] Closed for server '${this.serverName}'`,
+      );
+    }
+
+    if (this.onclose) {
+      this.onclose();
+    }
+  }
+
+  /**
+   * Check if transport is started
+   */
+  isStarted(): boolean {
+    return this.started;
+  }
+
+  /**
+   * Get server name
+   */
+  getServerName(): string {
+    return this.serverName;
+  }
+}