BSB plugins should be actual services (own port, lifecycle, resource
ownership). Moved secrets, auth, pairing, bundle, nodered-bridge, and
cec-relay from plugin folders to shared modules under server/src/shared/.
4 BSB plugins remain: service-store, service-admin-http,
service-api-http, service-coordinator-ws.
service-admin-http now initializes secrets + auth as plain modules in
init() using the store repo from the plugin-registry singleton. No
more setSiblings() hack or inter-plugin wiring.
sec-config.yaml updated: secrets/auth config moved into
service-admin-http, pairing config into service-api-http, nodered
config into service-coordinator-ws.
