New module crates/maestro-daemon/src/catalog_mirror.rs: in-memory mirror of the global catalog (peer daemons + their sessions), updated from the `DaemonInbound::CatalogEvent` frames the registry now fans out. `local_api` consumes it: `GET /api/sessions` returns the union of the daemon's own sessions and the mirrored peers; `GET /api/daemons` returns self + connected peers. The web UI sees the same catalog from any home daemon. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>