Cross-Region Observability and Monitoring with CloudWatch

Act as a Global Observability Lead. Design an uncompromising, unified observability framework specifically tailored for a chaotic, multi-region active-active serverless stack. Architect the setup of AWS CloudWatch Cross-Region Dashboards designed to seamlessly aggregate and visualize high-resolution [METRIC_GRANULARITY] (e.g., 1-minute period) data pulled simultaneously from all operating regions into a single, cohesive pane of glass based on the [DASHBOARD_TYPE] (e.g., Executive Summary vs. Deep Database Diagnostics). Configure advanced CloudWatch Composite Alarms mathematically engineered to trigger exclusively based on an [ALARM_THRESHOLD] that requires simultaneous failures across multiple regions, drastically reducing localized alert fatigue. Detail the exact SDK configuration required to inject AWS X-Ray trace headers to establish cross-region trace analysis, allowing SREs to physically track the latency bottlenecks of an API call bouncing between US-East and EU-West.