docs: add workflow guide for agent integration

Add comprehensive workflow guide covering:
- Authentication setup (API key and JWT)
- Basic query workflow with validation
- Streaming with SSE clients (Python/JS)
- Multi-database workflow
- Batch processing patterns
- Error handling and retry strategies
- Integration patterns (pipelines, chatbots, BI tools, Slack)
- Best practices for production use

Author: Sakeeb91

README.md

@@ -233,6 +233,7 @@ docker-compose up -d
 
 | Document | Description |
 |----------|-------------|
+| [Workflow Guide](docs/WORKFLOW_GUIDE.md) | Integration patterns and usage workflows |
 | [API Reference](docs/API.md) | Complete endpoint documentation |
 | [Configuration](docs/CONFIGURATION.md) | Environment variables and options |
 | [Deployment](docs/DEPLOYMENT.md) | Docker, Kubernetes, production |