Add Metrics Collection

Implement detailed metrics collection for monitoring and debugging.

Description: Collecting metrics about server performance and client behavior would be useful for monitoring and optimization.

Tasks:

• Add query timing metrics
• Add connection statistics
• Add memory usage tracking
• Add customizable logging for metrics
• Create dashboard template for metrics visualization
• Document available metrics

Related files:

• src/server/serverManager.js
• src/connection/connectionState.js
• src/handlers/queryHandlers.js