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>

src/types/index.ts

@@ -0,0 +1,37 @@
+export interface MCPServerConfig {
+  port: number;
+  host: string;
+  authToken?: string;
+}
+
+export interface N8NConfig {
+  apiUrl: string;
+  apiKey: string;
+}
+
+export interface ToolDefinition {
+  name: string;
+  description: string;
+  inputSchema: {
+    type: string;
+    properties: Record<string, any>;
+    required?: string[];
+  };
+}
+
+export interface ResourceDefinition {
+  uri: string;
+  name: string;
+  description?: string;
+  mimeType?: string;
+}
+
+export interface PromptDefinition {
+  name: string;
+  description?: string;
+  arguments?: Array<{
+    name: string;
+    description?: string;
+    required?: boolean;
+  }>;
+}