Advanced AI Prompt for Multi-Region Metric Aggregation and Dashboarding

Act as a Global Cloud Architect. Design a unified, cross-region, cross-account observability strategy utilizing AWS CloudWatch. Your primary objective is to seamlessly aggregate the specific [CRITICAL_METRICS] (e.g., Global API Latency, Total Active Connections) originating from the disparate regions defined in [REGIONS_LIST] into a single, centralized pane of glass. Explicitly describe the IAM Trust Policy and permissions required for the [CROSS_ACCOUNT_ROLE] to authorize the centralized monitoring account to securely fetch telemetry from production sub-accounts. Output the raw, massive JSON body definition required to provision the [DASHBOARD_NAME], ensuring it features comparative line graphs overlaying regional data. Detail the architectural implementation of using 'CloudWatch Metric Streams' paired with Kinesis Firehose to continuously push this global telemetry into a central S3 data lake for compliance retention.