component AP gateway: use the new `priority` argument of `addManagedNode`: priority is needed because we'll need to inspect former items on retract to check the Acitivy to use (it may be an `Undo` activity is some cases), and this must be done before the cache is updated by pubsub cache plugin. rel 370

version: "3.6"
services:

  prosody:
    image: libervia/prosody:demo
    build: prosody-demo

  backend:
    image: libervia/backend:dev-demo
    build: backend-dev-demo

  web:
    image: libervia/web:dev-demo
    build: libervia-web-dev-demo