Add "webhook" to KNOWN_WORKERS + the start-all preferred order so the
Config → Workers panel picks up the row automatically: heartbeat
subscription, start/stop controls via the existing systemd helper
(decnet-webhook.service.j2 already lands via decnet init's unit
glob), and the status-dot lifecycle all come for free.
Placed between mutator and the swarm-only agent/forwarder/updater
trio — matches the intended startup sequence (bus → api → data-plane
workers → egress → swarm management).
No frontend change needed; Config.tsx reads the worker list
dynamically from GET /api/v1/workers.