fix: Improve MCP server robustness and debugging

- Refactor  for more reliable project root detection, particularly when running within integrated environments like Cursor IDE. Includes deriving root from script path and avoiding fallback to '/'.
- Enhance error handling in :
    - Add detailed debug information (paths searched, CWD, etc.) to the error message when  is not found in the provided project root.
    - Improve clarity of error messages and potential solutions.
- Add verbose logging in  to trace session object content and the finally resolved project root path, aiding in debugging path-related issues.
- Add default values for  and  to the example  environment configuration.

mcp-server/src/tools/update-subtask.js

@@ -6,7 +6,8 @@
 import { z } from "zod";
 import {
   handleApiResult,
-  createErrorResponse
+  createErrorResponse,
+  getProjectRootFromSession
 } from "./utils.js";
 import { updateSubtaskByIdDirect } from "../core/task-master-core.js";
 
@@ -16,7 +17,7 @@ import { updateSubtaskByIdDirect } from "../core/task-master-core.js";
  */
 export function registerUpdateSubtaskTool(server) {
   server.addTool({
-    name: "update-subtask",
+    name: "update_subtask",
     description: "Appends additional information to a specific subtask without replacing existing content",
     parameters: z.object({
       id: z.string().describe("ID of the subtask to update in format \"parentId.subtaskId\" (e.g., \"5.2\")"),
@@ -30,20 +31,34 @@ export function registerUpdateSubtaskTool(server) {
           "Root directory of the project (default: current working directory)"
         ),
     }),
-    execute: async (args, { log }) => {
+    execute: async (args, { log, session, reportProgress }) => {
       try {
         log.info(`Updating subtask with args: ${JSON.stringify(args)}`);
+        await reportProgress({ progress: 0 });
         
-        // Call the direct function wrapper
-        const result = await updateSubtaskByIdDirect(args, log);
+        let rootFolder = getProjectRootFromSession(session, log);
         
-        // Log result
-        log.info(`${result.success ? `Successfully updated subtask with ID ${args.id}` : 'Failed to update subtask'}`);
+        if (!rootFolder && args.projectRoot) {
+          rootFolder = args.projectRoot;
+          log.info(`Using project root from args as fallback: ${rootFolder}`);
+        }
+        
+        const result = await updateSubtaskByIdDirect({
+          projectRoot: rootFolder,
+          ...args
+        }, log, { reportProgress, mcpLog: log, session});
+        
+        await reportProgress({ progress: 100 });
+        
+        if (result.success) {
+          log.info(`Successfully updated subtask with ID ${args.id}`);
+        } else {
+          log.error(`Failed to update subtask: ${result.error?.message || 'Unknown error'}`);
+        }
         
-        // Use handleApiResult to format the response
         return handleApiResult(result, log, 'Error updating subtask');
       } catch (error) {
-        log.error(`Error in update-subtask tool: ${error.message}`);
+        log.error(`Error in update_subtask tool: ${error.message}`);
         return createErrorResponse(error.message);
       }
     },