The standalone sweep script ran as a separate workflow step, so teardown
depended on that step and on a dry-run flag. Alchemy Actions never run on
destroy, so the sweep is a Resource instead: its delete sweeps the stage's
managed tunnels and their CNAMEs, and `alchemy destroy` runs it. The resource
depends on the Worker, so it is deleted before the Worker.

Co-Authored-By: Claude Haiku 5.5 <noreply@anthropic.com>