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;