A switching layout does not negotiate. Spur capacity, lead length, which end the runaround sits on: benchwork and a wall settled all of that, and the only thing a crew controls is the order of the moves. Everything in this release follows from that one fact. The district editor takes your track as a chain, each piece named by which end of which other piece it hangs off, and derives turnout geometry from the chain without asking you to describe it. The session runner puts six one-handed controls under a live schematic of that district and redraws it after every move. Legality is checked over coupled length, with fouling treated as a property of the turnout, and a refused move names the rule it broke. The line-out search plans from wherever the cars are standing now and minimises changes of direction under a two-second budget, reporting its best partial when it cannot reach a full answer. Industries state what they receive and ship and in which car types, cars carry four-cycle waybills, and a session opening turns those cards forward into the pulls and spots it hands you. The move journal is append-only, so a session can be rewound and driven again down a different line, and a reconcile at the end lets you correct what the app believes about the room. What all of it asks of you is real work. The district has to be entered by hand, track by track, before a first session, and a small town is a sitting's work. Over-coupler length and car type stop being decoration in the roster and become inputs the rules read, so a wrong length produces a wrong refusal. Fourteen tracks and twenty-four cars is the ceiling, which means a large railroad goes in one district at a time. The four readiness sliders are swept out on first launch, a slider position never having been evidence about anybody's layout. Nothing else the old build stored goes with them: an entry written like reporting marks and a number arrives as a car, the rest is kept verbatim as a note under the roster, and identical marks on two cars are flagged there so no message can mean either of them. Roster, District and Session are the three tabs. There is nothing else in it now.