fix(itinerary): add city to game items for proper constraint validation

Travel constraint validation was not working because ItineraryConstraints
had no game items to validate against - games came from RichGame objects
but were never converted to ItineraryItem for constraint checking.

Changes:
- Add city parameter to ItemKind.game enum case
- Create game ItineraryItems from RichGame data in buildItineraryData()
- Update isValidTravelPosition to compare against actual game sortOrders
- Fix tests to use appropriate game sortOrder conventions

Now travel is properly constrained to appear before arrival city games
and after departure city games.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

SportsTime/Export/PDFGenerator.swift

@@ -388,11 +388,9 @@ final class PDFGenerator {
         var primaryCity: String?
         for item in items {
             switch item.kind {
-            case .game(let gameId):
-                if let richGame = games[gameId] {
-                    primaryCity = richGame.stadium.city
-                    break
-                }
+            case .game(_, let city):
+                primaryCity = city
+                break
             case .travel(let info):
                 primaryCity = info.toCity
                 break
@@ -419,7 +417,7 @@ final class PDFGenerator {
         var hasContent = false
         for item in items {
             switch item.kind {
-            case .game(let gameId):
+            case .game(let gameId, _):
                 if let richGame = games[gameId] {
                     currentY = drawGameCard(
                         context: context,