Implement n8n-MCP integration

This commit adds a complete integration between n8n workflow automation and the Model Context Protocol (MCP):

Features:
- MCP server that exposes n8n workflows as tools, resources, and prompts
- Custom n8n node for connecting to MCP servers from workflows
- Bidirectional bridge for data format conversion
- Token-based authentication and credential management
- Comprehensive error handling and logging
- Full test coverage for core components

Infrastructure:
- TypeScript/Node.js project setup with proper build configuration
- Docker support with multi-stage builds
- Development and production docker-compose configurations
- Installation script for n8n custom node deployment

Documentation:
- Detailed README with usage examples and API reference
- Environment configuration templates
- Troubleshooting guide

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

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

docker-compose.yml

@@ -0,0 +1,49 @@
+version: '3.8'
+
+services:
+  n8n-mcp:
+    build: .
+    container_name: n8n-mcp-server
+    restart: unless-stopped
+    environment:
+      - MCP_SERVER_PORT=${MCP_SERVER_PORT:-3000}
+      - MCP_SERVER_HOST=${MCP_SERVER_HOST:-0.0.0.0}
+      - N8N_API_URL=${N8N_API_URL:-http://n8n:5678}
+      - N8N_API_KEY=${N8N_API_KEY}
+      - MCP_AUTH_TOKEN=${MCP_AUTH_TOKEN}
+      - LOG_LEVEL=${LOG_LEVEL:-info}
+    ports:
+      - "${MCP_SERVER_PORT:-3000}:3000"
+    networks:
+      - n8n-network
+    depends_on:
+      - n8n
+
+  n8n:
+    image: n8nio/n8n:latest
+    container_name: n8n
+    restart: unless-stopped
+    ports:
+      - "5678:5678"
+    environment:
+      - N8N_BASIC_AUTH_ACTIVE=true
+      - N8N_BASIC_AUTH_USER=${N8N_BASIC_AUTH_USER:-admin}
+      - N8N_BASIC_AUTH_PASSWORD=${N8N_BASIC_AUTH_PASSWORD:-password}
+      - N8N_HOST=${N8N_HOST:-localhost}
+      - N8N_PORT=5678
+      - N8N_PROTOCOL=${N8N_PROTOCOL:-http}
+      - NODE_ENV=production
+      - WEBHOOK_URL=${WEBHOOK_URL:-http://localhost:5678/}
+      - GENERIC_TIMEZONE=${GENERIC_TIMEZONE:-UTC}
+    volumes:
+      - n8n_data:/home/node/.n8n
+      - ./n8n-custom-nodes:/home/node/.n8n/custom
+    networks:
+      - n8n-network
+
+networks:
+  n8n-network:
+    driver: bridge
+
+volumes:
+  n8n_data: