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/utils/logger.ts

@@ -14,6 +14,8 @@ export interface LoggerConfig {
 export class Logger {
   private config: LoggerConfig;
   private static instance: Logger;
+  private useFileLogging = false;
+  private fileStream: any = null;
 
   constructor(config?: Partial<LoggerConfig>) {
     this.config = {
@@ -52,6 +54,13 @@ export class Logger {
     if (level <= this.config.level) {
       const formattedMessage = this.formatMessage(levelName, message);
       
+      // In HTTP mode during request handling, suppress console output
+      // The ConsoleManager will handle this, but we add a safety check
+      if (process.env.MCP_MODE === 'http' && process.env.MCP_REQUEST_ACTIVE === 'true') {
+        // Silently drop the log during active MCP requests
+        return;
+      }
+      
       switch (level) {
         case LogLevel.ERROR:
           console.error(formattedMessage, ...args);