Multi-Region ECS Fargate Deployment Strategy with Route 53 ARC

Act as a High-Availability Solutions Architect. Draft an impenetrable technical blueprint for a multi-region, active-passive ECS Fargate deployment physically spanning [PRIMARY_REGION] and a cold-standby [SECONDARY_REGION]. The absolute core of this architecture must utilize the AWS Route 53 Application Recovery Controller (ARC) to govern the geographic failover routing. Provide the exact Terraform HCL defining the strict ARC routing controls and the underlying Route 53 health checks configured with a severe [FAILOVER_THRESHOLD]. Detail the exact CI/CD event-driven logic required to guarantee that the primary ECS Task Definitions, SSM secrets, and Docker image tags are flawlessly and automatically synchronized to the secondary region on every single deployment.