Release v0.3.0 - Enhanced Health Checks and Prometheus Metrics Integration

This release introduces significant improvements to the spark-middleware project, focusing on enhanced monitoring and readiness features:

• Kubernetes Health Endpoints: Added livez and readyz endpoints for Kubernetes liveness and readiness checks. The readyz endpoint now responds positively only after the system has completed historical data synchronization and is actively processing current data.
• Prometheus Metrics Integration: Introduced basic metrics for monitoring with Prometheus and Grafana, including order processing statistics and error tracking.