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/intents.ts

@@ -17,7 +17,13 @@ export type Intent =
   | { type: 'localOps.choose'; option: LocalOpsOption }
   // -- switch (§6.1, Appendix A)
   | { type: 'switch.move'; trayId: TrayId; to: GridCoord; reverse: boolean }
-  | { type: 'switch.dropCars'; trayId: TrayId; count: number }
+  /**
+   * Set out a cut. `fromNose` takes it off the FRONT of the train rather than the back — Appendix A's
+   * worked example does exactly this: "Back up and drop off everything on the nose of your train
+   * (red and blue) on Card B." Without it, cars taken onto the nose could never be set out again and
+   * an engine buried in its own train had no way back to an end.
+   */
+  | { type: 'switch.dropCars'; trayId: TrayId; count: number; fromNose?: boolean }
   /**
    * Small Yard enhancement — "a train that spends one move in the yard may sort itself in any
    * order, including cars in front of the engine". This is the designed answer to §A.3's
@@ -28,16 +34,13 @@ export type Intent =
   // -- draw (§6.2)
   | { type: 'draw.fromHomeOffice' }
   | { type: 'draw.fromDepartment'; slot: number }
-  /** `variant` indexes `variantsFor(geometry)` — Gap 11: orientation is chosen on placement. */
+  /**
+   * `variant` indexes `variantsFor(geometry, hand)` — 0° or 180°, the only two ways a printed card
+   * can be laid. Track is played through here like every other card; there is no separate lay
+   * intent, because there is no separate supply to lay from.
+   */
   | { type: 'card.play'; cardId: CardId; placement?: GridCoord; variant?: number }
   | { type: 'card.discard'; cardId: CardId; toSlot: number }
-  /**
-   * Lay a piece from your personal track supply (§12.2 / content.ts TRACK_SUPPLY).
-   *
-   * Laid during the "draw a card" option, one piece a turn — how track behaved when it WAS a card.
-   * Confirmed; see implications.md §10 Q10.
-   */
-  | { type: 'track.lay'; geometry: TrackGeometry; hand: Hand; placement: GridCoord; variant?: number }
   | { type: 'draw.end' }
   // -- freight agent (§6.3)
   | { type: 'freightAgent.stockOutbound'; at: GridCoord; carType: CarType }
@@ -110,6 +113,8 @@ export type RejectionCode =
   | 'NO_PENDING_DECISION'
   | 'NOT_UPGRADEABLE'
   | 'FACILITY_LOCKED'
+  /** An Industry goes on a straight stub, never on the Running Track (sheet: "Placed" column). */
+  | 'ON_RUNNING_TRACK'
   | 'NOT_IMPLEMENTED'
   | 'WRONG_INTENT'
   | 'NOT_A_GRADE'