Implement SQLite database with full-text search for n8n node documentation

Major features implemented:
- SQLite storage service with FTS5 for fast node search
- Database rebuild mechanism for bulk node extraction
- MCP tools: search_nodes, extract_all_nodes, get_node_statistics
- Production Docker deployment with persistent storage
- Management scripts for database operations
- Comprehensive test suite for all functionality

Database capabilities:
- Stores node source code and metadata
- Full-text search by node name or content
- No versioning (stores latest only as per requirements)
- Supports complete database rebuilds
- ~4.5MB database with 500+ nodes indexed

Production features:
- Automated deployment script
- Docker Compose production configuration
- Database initialization on first run
- Volume persistence for data
- Management utilities for operations

Documentation:
- Updated README with complete instructions
- Production deployment guide
- Clear troubleshooting section
- API reference for all new tools

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

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

.env.example

@@ -1,13 +1,22 @@
-# MCP Server Configuration
-MCP_SERVER_PORT=3000
-MCP_SERVER_HOST=localhost
-
 # n8n Configuration
-N8N_API_URL=http://localhost:5678
-N8N_API_KEY=your-n8n-api-key
+N8N_BASIC_AUTH_USER=admin
+N8N_BASIC_AUTH_PASSWORD=your-secure-password-here
+N8N_HOST=localhost
+N8N_API_KEY=your-api-key-here
+
+# MCP Configuration
+MCP_LOG_LEVEL=info
+NODE_ENV=production
+
+# Database Configuration
+NODE_DB_PATH=/app/data/nodes.db
+
+# Optional: External n8n instance
+# N8N_API_URL=http://your-n8n-instance:5678
+
+# MCP Server Configuration (if using HTTP transport)
+# MCP_SERVER_PORT=3000
+# MCP_SERVER_HOST=localhost
 
 # Authentication
-MCP_AUTH_TOKEN=your-secure-token
-
-# Logging
-LOG_LEVEL=info
+# MCP_AUTH_TOKEN=your-secure-token