fix: implement Single-Session architecture to resolve MCP stream errors

- Add ConsoleManager to prevent console output interference with StreamableHTTPServerTransport
- Implement SingleSessionHTTPServer with persistent session reuse
- Create N8NMCPEngine for clean service integration
- Add automatic session expiry after 30 minutes of inactivity
- Update logger to be HTTP-aware during active requests
- Maintain backward compatibility with existing deployments

This fixes the "stream is not readable" error by implementing the Hybrid
Single-Session architecture as documented in MCP_ERROR_FIX_PLAN.md

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/index.ts

@@ -4,48 +4,15 @@
  * Licensed under the Sustainable Use License v1.0
  */
 
-import dotenv from 'dotenv';
-import { N8NMCPServer } from './mcp/server';
-import { MCPServerConfig, N8NConfig } from './types';
-import { logger } from './utils/logger';
+// Engine exports for service integration
+export { N8NMCPEngine, EngineHealth, EngineOptions } from './mcp-engine';
+export { SingleSessionHTTPServer } from './http-server-single-session';
+export { ConsoleManager } from './utils/console-manager';
+export { N8NDocumentationMCPServer } from './mcp/server-update';
 
-// Load environment variables
-dotenv.config();
+// Default export for convenience
+import N8NMCPEngine from './mcp-engine';
+export default N8NMCPEngine;
 
-async function main() {
-  const config: MCPServerConfig = {
-    port: parseInt(process.env.MCP_SERVER_PORT || '3000', 10),
-    host: process.env.MCP_SERVER_HOST || 'localhost',
-    authToken: process.env.MCP_AUTH_TOKEN,
-  };
-
-  const n8nConfig: N8NConfig = {
-    apiUrl: process.env.N8N_API_URL || 'http://localhost:5678',
-    apiKey: process.env.N8N_API_KEY || '',
-  };
-
-  const server = new N8NMCPServer(config, n8nConfig);
-  
-  try {
-    await server.start();
-  } catch (error) {
-    logger.error('Failed to start MCP server:', error);
-    process.exit(1);
-  }
-}
-
-// Handle graceful shutdown
-process.on('SIGINT', () => {
-  logger.info('Received SIGINT, shutting down MCP server...');
-  process.exit(0);
-});
-
-process.on('SIGTERM', () => {
-  logger.info('Received SIGTERM, shutting down MCP server...');
-  process.exit(0);
-});
-
-main().catch((error) => {
-  logger.error('Unhandled error:', error);
-  process.exit(1);
-});
+// Legacy CLI functionality - moved to ./mcp/index.ts
+// This file now serves as the main entry point for library usage