Track becomes a deck card, Departments become decks, and trains must be made up to leave, industry restrictions enforced, update display and add a new game button

src/engine/state.ts

@@ -9,6 +9,7 @@
 import type {
   CarType,
   Direction,
+  Hand,
   MainlineKind,
   FreightKind,
   GameLength,
@@ -127,11 +128,6 @@ export type OfficeArea = {
   heldAtLimits: TrayId[];
   /** Dispatch bonuses spent this Day, by enhancement key — each is once a Day. */
   dispatchUsedToday: string[];
-  /**
-   * The player's personal track supply (26 pieces), keyed `geometry:hand`. Track is NOT in the
-   * Home Office deck — it is laid from here.
-   */
-  trackSupply: Map<string, number>;
 };
 
 // ---------------------------------------------------------------------------
@@ -192,10 +188,24 @@ export function spaceOn(card: TrackCard): number {
 
 export function isOperationalRail(card: TrackCard): boolean {
   if (!card.baseOperationalRail) return false;
-  if (card.facility && card.facility.menAtWork.some((slot) => slot !== null)) return false;
+  if (isLockedByWork(card)) return false;
   return true;
 }
 
+/**
+ * §9.3 — "While ANY loads are in the MEN | AT | WORK track, the industry's track is locked down for
+ * safety reasons. It loses its status as Operational Rail. No cars can be picked up or dropped off,
+ * and **no trains may occupy or move on it**."
+ *
+ * That last clause is stronger than losing Operational Rail status. A turnout is not Operational
+ * Rail either, and a train runs straight through one — so "cannot stop here" and "cannot pass
+ * through here" are different properties, and only a locked industry has both. Kept separate from
+ * `isOperationalRail` for exactly that reason.
+ */
+export function isLockedByWork(card: TrackCard): boolean {
+  return !!card.facility && card.facility.menAtWork.some((slot) => slot !== null);
+}
+
 // ---------------------------------------------------------------------------
 // Trains
 // ---------------------------------------------------------------------------
@@ -223,7 +233,16 @@ export type CrewTray = {
    * the four-car limit (§A.4) is a limit on cars, not on the locomotive hauling them.
    */
   engineAt: number;
-  /** ORDERED, left-to-right. Max 4 including any caboose (§A.4). */
+  /**
+   * ORDERED NOSE FIRST: index 0 is the end nearest the front of the train, the last index is the
+   * tail. Max 4 including any caboose (§A.4); the engine is not one of them.
+   *
+   * Both diagrams in Appendix A read this way. A train drawn `[<ENG][yellow][brown][blue][red]`
+   * drops "red as he starts, then brown and blue", ending with only yellow — cars come off the TAIL,
+   * which is the end of the array. And a train that picks cars up on its nose gets them "in the
+   * order that they were in, pushing them into the Facility" — ahead of the engine, which is why
+   * `engineAt` moves when it happens.
+   */
   consist: RollingStock[];
   direction: Direction;
   /**
@@ -298,7 +317,8 @@ export type CardKind =
   | { kind: 'office'; tier: OfficeTier }
   | { kind: 'freightFacility'; facility: FreightKind }
   | { kind: 'modifier'; modifier: ModifierKind }
-  | { kind: 'track'; geometry: TrackGeometry }
+  /** Handedness is printed on the card: it is the diagonal the 45° leg lies on. */
+  | { kind: 'track'; geometry: TrackGeometry; hand: Hand }
   /**
    * The four categories recovered from the design. They are in the deck so the composition is
    * right; their BEHAVIOUR is not implemented yet (implications.md §10 is still open), so
@@ -315,8 +335,18 @@ export type Card = { id: CardId; kind: CardKind };
 export type Decks = {
   /** Face down. Order is SECRET — never projected to any client. */
   homeOffice: CardId[];
-  /** Three face-up market slots fed from the deck (§2.6). */
-  departments: (CardId | null)[];
+  /**
+   * THE THREE DEPARTMENT DECKS — shared by every player, and stacks rather than single slots.
+   *
+   * §6.2: a discard goes "face up ON TOP of one of the three Department slots", and a draw takes
+   * "the TOP face-up card". Both phrases only mean anything if a Department is a pile, and modelling
+   * them as one-card slots silently DESTROYED whatever was underneath — discarding onto an occupied
+   * slot overwrote it, leaking cards out of a closed deck.
+   *
+   * Last element is the top of the pile: the card that is face up, the only one that may be drawn,
+   * and the one a discarding player is choosing to offer or to bury.
+   */
+  departments: CardId[][];
   /** Face up, so players can audit discards (§2.6). */
   salvageYard: CardId[];
   /** Private to the owner. Max 3, or 4 with a Red Flag. */
@@ -412,11 +442,6 @@ export type TurnState = {
   option: 'switch' | 'draw' | 'freightAgent' | null;
   movesRemaining: number;
   drawnThisTurn: boolean;
-  /**
-   * Track was a CARD before it became a per-player supply, so it was naturally limited to one play
-   * a turn. The supply has 26 pieces and nothing else bounds it, so keep that limit explicitly.
-   */
-  laidThisTurn: boolean;
   freightAgentUsed: boolean;
   /** Set when the actor finishes; the phase driver then moves to the next player. */
   done: boolean;
@@ -427,7 +452,6 @@ export function freshTurn(moves: number): TurnState {
     option: null,
     movesRemaining: moves,
     drawnThisTurn: false,
-    laidThisTurn: false,
     freightAgentUsed: false,
     done: false,
   };