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/mcp/tools.ts

@@ -0,0 +1,148 @@
+import { ToolDefinition } from '../types';
+
+export const n8nTools: ToolDefinition[] = [
+  {
+    name: 'execute_workflow',
+    description: 'Execute an n8n workflow by ID',
+    inputSchema: {
+      type: 'object',
+      properties: {
+        workflowId: {
+          type: 'string',
+          description: 'The ID of the workflow to execute',
+        },
+        data: {
+          type: 'object',
+          description: 'Input data for the workflow execution',
+        },
+      },
+      required: ['workflowId'],
+    },
+  },
+  {
+    name: 'list_workflows',
+    description: 'List all available n8n workflows',
+    inputSchema: {
+      type: 'object',
+      properties: {
+        active: {
+          type: 'boolean',
+          description: 'Filter by active status',
+        },
+        tags: {
+          type: 'array',
+          items: { type: 'string' },
+          description: 'Filter by tags',
+        },
+      },
+    },
+  },
+  {
+    name: 'get_workflow',
+    description: 'Get details of a specific workflow',
+    inputSchema: {
+      type: 'object',
+      properties: {
+        id: {
+          type: 'string',
+          description: 'The workflow ID',
+        },
+      },
+      required: ['id'],
+    },
+  },
+  {
+    name: 'create_workflow',
+    description: 'Create a new n8n workflow',
+    inputSchema: {
+      type: 'object',
+      properties: {
+        name: {
+          type: 'string',
+          description: 'Name of the workflow',
+        },
+        nodes: {
+          type: 'array',
+          description: 'Array of node definitions',
+        },
+        connections: {
+          type: 'object',
+          description: 'Node connections',
+        },
+        settings: {
+          type: 'object',
+          description: 'Workflow settings',
+        },
+      },
+      required: ['name'],
+    },
+  },
+  {
+    name: 'update_workflow',
+    description: 'Update an existing workflow',
+    inputSchema: {
+      type: 'object',
+      properties: {
+        id: {
+          type: 'string',
+          description: 'The workflow ID',
+        },
+        updates: {
+          type: 'object',
+          description: 'Updates to apply to the workflow',
+        },
+      },
+      required: ['id', 'updates'],
+    },
+  },
+  {
+    name: 'delete_workflow',
+    description: 'Delete a workflow',
+    inputSchema: {
+      type: 'object',
+      properties: {
+        id: {
+          type: 'string',
+          description: 'The workflow ID to delete',
+        },
+      },
+      required: ['id'],
+    },
+  },
+  {
+    name: 'get_executions',
+    description: 'Get workflow execution history',
+    inputSchema: {
+      type: 'object',
+      properties: {
+        workflowId: {
+          type: 'string',
+          description: 'Filter by workflow ID',
+        },
+        status: {
+          type: 'string',
+          enum: ['success', 'error', 'running', 'waiting'],
+          description: 'Filter by execution status',
+        },
+        limit: {
+          type: 'number',
+          description: 'Maximum number of executions to return',
+        },
+      },
+    },
+  },
+  {
+    name: 'get_execution_data',
+    description: 'Get detailed data for a specific execution',
+    inputSchema: {
+      type: 'object',
+      properties: {
+        executionId: {
+          type: 'string',
+          description: 'The execution ID',
+        },
+      },
+      required: ['executionId'],
+    },
+  },
+];