- NodeDef `device`/`device_policy` become `worker`/`worker_policy`, the
issue `ignored_device` becomes `ignored_worker`, and the SDK's `@node`
takes `worker=` and `worker_policy=`
- FlowStore._migrate renames the keys in published and draft documents
once, bumping their version; a queued run's `needs` reads the old key
- placement passes the label as `label`, client regenerated
- docs: worker placement wording, MCP issuer without DOMAIN, device rows in
the CLI data directory and the API table, device links in compose comments