docs(meta): D-254 — standalone Atlas companion app (make atlas, dual-connection reader) (T-1129)
Six sections: connection model (attach SR_PORT/9876 ~500ms else spawn --port 0 + LISTENING parse, auto-attach-else-spawn); Reader connection class (ConnectionRole on StartupMessage, serde-default Player; no character spawn, NO ObserverSnapshot, permitted-message matrix, drop-not-disconnect, 0-1 Player + 0-N Readers, Player-only shutdown-on-disconnect); app shell (dedicated atlas_standalone.tscn, trivial make atlas target); data browser (separate implant/browser app per Jeroen, six registry entities v1, WIRE-ONLY extending the T-949 precedent — no client SQLite); save/load seam (seed picker now, save picker slot Phase 5+); trading seam (TradingReader superset, idempotency tokens, loopback-only auth assumption recorded). Tyre (lead) + Oscar (connection sections, his activation). Validate + sync clean (388 records, 0 broken).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>