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/mcp/index.ts

@@ -25,9 +25,20 @@ async function main() {
     console.error('Node version:', process.version);
     
     if (mode === 'http') {
-      // HTTP mode - for remote deployment
-      const { startHTTPServer } = await import('../http-server');
-      await startHTTPServer();
+      // HTTP mode - for remote deployment with single-session architecture
+      const { SingleSessionHTTPServer } = await import('../http-server-single-session');
+      const server = new SingleSessionHTTPServer();
+      
+      // Graceful shutdown handlers
+      const shutdown = async () => {
+        await server.shutdown();
+        process.exit(0);
+      };
+      
+      process.on('SIGTERM', shutdown);
+      process.on('SIGINT', shutdown);
+      
+      await server.start();
     } else {
       // Stdio mode - for local Claude Desktop
       const server = new N8NDocumentationMCPServer();