Fix parking trains, freight deadlock, and Whistle Post lock-in

src/engine/content.ts

@@ -105,11 +105,30 @@ export type OfficeProfile = {
  * an earlier guess gave one more slot than porters at every tier. Capacity is instead grown by the
  * passenger modifier cards (Waiting Area, Restaurant, Hotel).
  */
+/**
+ * Office cards. `copiesInDeck` was **doubled** (Depot 4→8, Station 2→4, Terminal 1→2) — Q12.
+ *
+ * Players always start at a Whistle Post, which has ONE A/D track, so a second arrival is an
+ * automatic collision (§8.3, Gap 2a). Measured at the original density, 25 of 100 games never drew
+ * a Depot and never escaped: they averaged **−6.0** revenue against **−0.4** for games that
+ * upgraded at least once, and 25 of 26 collisions happened at Whistle Post. Escaping needed one of
+ * 4 Depot cards in 111, roughly a 59% chance across a game's draws.
+ *
+ * Upgrades are strictly sequential (Gap 3b, no skipping), so Station and Terminal are rarer than
+ * their raw counts imply — Terminal needs all three cards in order. Station and Terminal were
+ * doubled with Depot to keep that ladder in proportion rather than making Depot a special case.
+ *
+ * PROVISIONAL — re-evaluate. This was chosen to remove a 25% chance of an unwinnable opening deal,
+ * not from the recovered design, and it is a blunt instrument: it lifts the whole office ladder and
+ * dilutes every other category slightly (deck 133 → 140). Revisit once the victory target is
+ * settled and freight is carrying its intended share; the right answer may instead be fewer
+ * Terminals, a cheaper first upgrade, or more A/D capacity at Whistle Post.
+ */
 export const OFFICE_PROFILES: readonly OfficeProfile[] = [
   { tier: 'whistlePost', name: 'Whistle Post', isControlPoint: false, isPassengerFacility: false, adTracks: 1, porters: 0, passengerOut: 0, passengerIn: 0, copiesInDeck: 0 },
-  { tier: 'depot', name: 'Depot', isControlPoint: true, isPassengerFacility: true, adTracks: 2, porters: 1, passengerOut: 1, passengerIn: 1, copiesInDeck: 4 },
-  { tier: 'station', name: 'Station', isControlPoint: true, isPassengerFacility: true, adTracks: 3, porters: 2, passengerOut: 2, passengerIn: 2, copiesInDeck: 2 },
-  { tier: 'terminal', name: 'Terminal', isControlPoint: true, isPassengerFacility: true, adTracks: 4, porters: 3, passengerOut: 3, passengerIn: 3, copiesInDeck: 1 },
+  { tier: 'depot', name: 'Depot', isControlPoint: true, isPassengerFacility: true, adTracks: 2, porters: 1, passengerOut: 1, passengerIn: 1, copiesInDeck: 8 },
+  { tier: 'station', name: 'Station', isControlPoint: true, isPassengerFacility: true, adTracks: 3, porters: 2, passengerOut: 2, passengerIn: 2, copiesInDeck: 4 },
+  { tier: 'terminal', name: 'Terminal', isControlPoint: true, isPassengerFacility: true, adTracks: 4, porters: 3, passengerOut: 3, passengerIn: 3, copiesInDeck: 2 },
 ];
 
 export const OFFICE_ORDER: readonly OfficeTier[] = ['whistlePost', 'depot', 'station', 'terminal'];
@@ -393,6 +412,7 @@ export function crossingStages(
   carriesPassengers: boolean,
   modifiers: readonly string[] = [],
   direction: Direction = 'east',
+  gradeUp: Direction = 'east',
 ): number {
   const profile = MAINLINE_PROFILES.find((m) => m.kind === kind);
   if (!profile) throw new Error(`unknown mainline card: ${kind}`);
@@ -414,15 +434,13 @@ export function crossingStages(
 
   const base = mph >= 60 ? 1 : 2;
   const stages = base + (trainSpeed === 'slow' ? 1 : 0);
-  return Math.max(1, stages - gradeReduction(profile, modifiers, direction));
+  return Math.max(1, stages - gradeReduction(profile, modifiers, direction, gradeUp));
 }
 
 /**
- * ASSUMPTION, flagged (§10 Q11): the recovered sheet says Brakeman and Airbrakes give "faster
- * passage downhill" and Helpers "faster passage uphill", but never says which way a Heavy Grade
- * climbs. Modelled as **climbing eastward** — an eastbound train is going uphill, a westbound one
- * downhill. Needs confirming; if grades instead carry their own direction, this becomes a property
- * of the Mainline node rather than a constant.
+ * Q11, answered: the Heavy Grade card prints "(Up)" and "Player sets orientation", so which way it
+ * climbs is a property of the placed card, not a constant. `gradeUp` is the direction a train is
+ * travelling when it goes UPHILL; a train heading the other way is descending.
  *
  * Each applicable card takes a Stage off, never below one: a train cannot cross in no time.
  * Airbrakes only counts when Brakeman is already there, which the placement rule enforces.
@@ -431,9 +449,10 @@ function gradeReduction(
   profile: MainlineProfile,
   modifiers: readonly string[],
   direction: Direction,
+  gradeUp: Direction,
 ): number {
   if (profile.speed.kind !== 'grade') return 0;
-  const downhill = direction === 'west';
+  const downhill = direction !== gradeUp;
   let n = 0;
   if (downhill) {
     if (modifiers.includes('brakeman')) n++;
@@ -648,7 +667,7 @@ export function lengthProfile(length: GameLength): LengthProfile {
 }
 
 // ---------------------------------------------------------------------------
-// Deck composition — 133 cards
+// Deck composition — 140 cards
 // ---------------------------------------------------------------------------
 
 /**
@@ -676,9 +695,9 @@ export function deckComposition(): { category: string; count: number }[] {
   ];
 }
 
-export const DECK_SIZE = deckComposition().reduce((n, c) => n + c.count, 0); // 133
+export const DECK_SIZE = deckComposition().reduce((n, c) => n + c.count, 0); // 140
 
-/** The solitaire deck drops the 22 opponent-directed cards, leaving 111. */
+/** The solitaire deck drops the 22 opponent-directed cards, leaving 118. */
 export const SOLITAIRE_DECK_SIZE = deckComposition()
   .filter((c) => !isOpponentOnly(c.category))
   .reduce((n, c) => n + c.count, 0);