retainForTerraformAdoption=true adds the required ManageSiteInfrastructure
parameter, conditions the 13 transferred resources and the S3 auto-delete
custom resource on it, applies Retain policies, pins the live dev origin
ID, attaches the deploy boundary and HcpTerraformWorkspace tag, and
narrows the OIDC subject to StringEquals. Normal synthesis is unchanged;
template tests cover both modes.
Self-contained CDK app (S3 + CloudFront + OIDC deploy role) deployed via the org reusable cd-cdk.yaml. Frontend served on dev.seahaven.com with the *.seahaven.com cert and a Route 53 apex alias; the SPA calls the dev backend directly at https://api.dev.seahaven.com/api.
