Draw freight on the card, and teach the bot to build a railroad

src/engine/advance.ts

@@ -755,6 +755,26 @@ function shiftChange(s: GameState, events: GameEvent[]): AdvanceResult {
   if (s.clock.stage >= STAGES_PER_DAY) {
     // Telegraph/Telephone/Radio are each usable once a Day.
     for (const area of s.officeAreas.values()) area.dispatchUsedToday = [];
+
+    /**
+     * THE CLASSIFICATION YARD GOES BACK INTO SERVICE OVERNIGHT.
+     *
+     * ASSUMPTION, flagged rather than derived: Gap 2c says engines and cabooses return to the
+     * Division Yard and everything else to Classification, and the recovered rules never say how
+     * Classification empties. It was write-only — seven places pushed into it and nothing ever read
+     * it — so rolling stock drained one way and left the game. Measured at 30 cars a game dead by
+     * the end, 37% of the 80 dealt at setup.
+     *
+     * Sorting cars for redistribution is what a classification yard is FOR, and a Day is its
+     * natural cycle, so they return at the Day boundary. This does not bind a 5-Day game — the
+     * Division Yard still held 16.6 loaded freight cars at the end and ran dry in 2 games of 100 —
+     * but a campaign-length game would have starved.
+     */
+    if (s.yards.classificationYard.length > 0) {
+      s.yards.divisionYard.push(...s.yards.classificationYard);
+      s.yards.classificationYard = [];
+    }
+
     s.clock.day += 1;
     s.clock.stage = 1;
     s.collisionsToday = 0;

src/engine/apply.ts

@@ -149,9 +149,23 @@ export function hasFreightAgentOption(s: GameState, player: PlayerIndex): boolea
  * for an empty coach to be spotted on a hopper siding, and because a load parked on MEN|AT|WORK
  * strips the industry track of Operational Rail status (§9.3), the facility would jam permanently.
  */
+/**
+ * EVERY commodity a facility handles, not just the first one printed.
+ *
+ * Two of the six industries take two: a Power Plant burns coal OR oil (`['hopper','tank']`) and a
+ * Grocer's Warehouse receives dry goods OR perishables (`['boxcar','reefer']`). This used to return
+ * `carTypes[0]`, and because `freightAgent.stockOutbound` gates on it, the engine rejected the
+ * second commodity as WRONG_CAR_TYPE — the sheet said a Power Plant takes tank cars and the code
+ * said it did not. Measured effect: tank cars were dropped 0 times in 100 games.
+ */
+export function facilityCarTypes(f: Facility): readonly CarType[] {
+  if (f.kind !== 'freight') return f.kind === 'passenger' ? ['coach'] : [];
+  return FREIGHT_PROFILES.find((p) => p.kind === f.subtype)?.carTypes ?? [];
+}
+
+/** The commodity to NAME a facility by, where one word is wanted. Legality must use the full set. */
 export function facilityCarType(f: Facility): CarType | null {
-  if (f.kind !== 'freight') return f.kind === 'passenger' ? 'coach' : null;
-  return FREIGHT_PROFILES.find((p) => p.kind === f.subtype)?.carTypes[0] ?? null;
+  return facilityCarTypes(f)[0] ?? null;
 }
 
 export function hasSwitchOption(s: GameState, player: PlayerIndex): boolean {
@@ -433,8 +447,8 @@ export function check(s: GameState, player: PlayerIndex, i: Intent): RejectionCo
       if (!f) return 'NO_SUCH_FACILITY';
       if (!f.allows.outbound) return 'NO_SUCH_FACILITY';
       if (f.outboundBox.length >= f.capacity.outbound) return 'BOX_FULL';
-      // §9.1 — the green box takes only this facility's commodity.
-      if (facilityCarType(f) !== i.carType) return 'WRONG_CAR_TYPE';
+      // §9.1 — the green box takes only this facility's commodities, of which it may have two.
+      if (!facilityCarTypes(f).includes(i.carType)) return 'WRONG_CAR_TYPE';
       if (!s.yards.divisionYard.some((c) => c.type === i.carType && c.loaded)) {
         return 'NO_SUITABLE_CAR';
       }