Sources + Tag Bus

The adapter registry is the inbound shore — Mongo, Postgres, S3, MQTT, Redis, Kafka — anywhere external data enters a public Zeq machine, source-audit stamps it and the row lands in data_source_audits. The tag bus is the outbound shore: any emit action on a public machine carries an optional tag:NAME, broadcasting to every cross-slug subscriber listening for that tag. Counts only — payloads stay owner-gated.