Cloudflare generates no preview URLs for a Worker that implements a Durable Object, so every
--preview-alias upload of orca-sandbox-control-dev 404ed. The runner DO moves to
orca-sandbox-build-runner-dev (wrangler.build-runner.dev.jsonc); the control plane binds it with
script_name and deletes its own class (migration env-build-runner-v2). The runner only keeps the
alarm: each step calls back into the control plane's BuildTicker RPC entrypoint, which runs the same
tickBuild with the control plane's D1, provider and secrets, so nothing is duplicated.