* fix: isolate dev CDK deploys on their own bootstrap qualifier (B-1)
Dev synthesizes against the oswedev qualifier and the dev infra deploy role
is scoped to cdk-oswedev-* — it can no longer assume the default hnb659fds
bootstrap roles whose admin cfn-exec-role deploys prod, closing the cross-env
escalation (OSWE-IAC-01). Prod stays on the default qualifier.
* test: assert per-env bootstrap qualifier isolation + document (B-1)
