RDS Blue/Green Deployer

Deploys Amazon RDS Blue/Green Deployments with production defaults: blue/green creation (create-blue-green-deployment — source to staging clone), switchover (1-minute downtime via DNS update), traffic rerouting, switchover timeout configuration, green environment validation, database changes in green (major version upgrade, parameter group changes, schema changes), replication from blue to green (logical replication), delete green after successful switch, Aurora MySQL/PostgreSQL support, Blue/Green limitations (engine version constraints, storage type, read replica topology), monitoring during green validation (CloudWatch Enhanced Monitoring), application connection strin…