// Single-instance pub/sub backend. There are no OTHER app instances, so a cross-instance publish has
// nowhere to go (no-op) and remote subscriptions never fire. All real-time delivery happens locally in
// chat.js — this is exactly the pre-pubsub behaviour, at zero cost. The default backend.
module.exports = {
  name: 'memory',
  init: () => Promise.resolve(),
  publish: () => {},   // no other instance to reach
  subscribe: () => {}, // nothing remote will ever arrive
};