Refactor to focused n8n node documentation MCP server

Major refactoring to align with actual requirements:
- Purpose: Serve n8n node code/documentation to AI agents only
- No workflow execution or management features
- Complete node information including source code, docs, and examples

New features:
- Node documentation service with SQLite FTS5 search
- Documentation fetcher from n8n-docs repository
- Example workflow generator for each node type
- Simplified MCP tools focused on node information
- Complete database rebuild with all node data

MCP Tools:
- list_nodes: List available nodes
- get_node_info: Get complete node information
- search_nodes: Full-text search across nodes
- get_node_example: Get usage examples
- get_node_source_code: Get source code only
- get_node_documentation: Get documentation only
- rebuild_database: Rebuild entire database
- get_database_statistics: Database stats

Database schema includes:
- Node source code and metadata
- Official documentation from n8n-docs
- Generated usage examples
- Full-text search capabilities
- Category and type filtering

Updated README with:
- Clear purpose statement
- Claude Desktop installation instructions
- Complete tool documentation
- Troubleshooting guide

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

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

tests/test-small-rebuild.js

@@ -0,0 +1,62 @@
+#!/usr/bin/env node
+
+const { NodeDocumentationService } = require('../dist/services/node-documentation-service');
+
+async function testSmallRebuild() {
+  console.log('Testing small rebuild...\n');
+  
+  const service = new NodeDocumentationService('./data/nodes-v2-test.db');
+  
+  try {
+    // First, let's just try the IF node specifically
+    const extractor = service.extractor;
+    console.log('1️⃣ Testing extraction of IF node...');
+    
+    try {
+      const ifNodeData = await extractor.extractNodeSource('n8n-nodes-base.If');
+      console.log('   ✅ Successfully extracted IF node');
+      console.log('   Source code length:', ifNodeData.sourceCode.length);
+      console.log('   Has credentials:', !!ifNodeData.credentialCode);
+    } catch (error) {
+      console.log('   ❌ Failed to extract IF node:', error.message);
+    }
+    
+    // Try the Webhook node
+    console.log('\n2️⃣ Testing extraction of Webhook node...');
+    try {
+      const webhookNodeData = await extractor.extractNodeSource('n8n-nodes-base.Webhook');
+      console.log('   ✅ Successfully extracted Webhook node');
+      console.log('   Source code length:', webhookNodeData.sourceCode.length);
+    } catch (error) {
+      console.log('   ❌ Failed to extract Webhook node:', error.message);
+    }
+    
+    // Now try storing just these nodes
+    console.log('\n3️⃣ Testing storage of a single node...');
+    const nodeInfo = {
+      nodeType: 'n8n-nodes-base.If',
+      name: 'If',
+      displayName: 'If',
+      description: 'Route items based on comparison operations',
+      sourceCode: 'test source code',
+      packageName: 'n8n-nodes-base',
+      hasCredentials: false,
+      isTrigger: false,
+      isWebhook: false
+    };
+    
+    await service.storeNode(nodeInfo);
+    console.log('   ✅ Successfully stored test node');
+    
+    // Check if it was stored
+    const retrievedNode = await service.getNodeInfo('n8n-nodes-base.If');
+    console.log('   Retrieved node:', retrievedNode ? 'Found' : 'Not found');
+    
+  } catch (error) {
+    console.error('❌ Test failed:', error);
+  } finally {
+    service.close();
+  }
+}
+
+testSmallRebuild();