fix: codebase audit fixes — safety, accessibility, and production hygiene

Address 16 issues from external audit:
- Move StoreKit transaction listener ownership to StoreManager singleton with proper deinit
- Remove noisy VoiceOver announcements, add missing accessibility on StatPill and BootstrapLoadingView
- Replace String @retroactive Identifiable with IdentifiableShareCode wrapper
- Add crash guard in AchievementEngine getContributingVisitIds + cache stadium lookups
- Pre-compute GamesHistoryViewModel filtered properties to avoid redundant SwiftUI recomputation
- Remove force-unwraps in ProgressMapView with safe guard-let fallback
- Add diff-based update gating in ItineraryTableViewWrapper to prevent unnecessary reloads
- Replace deprecated UIScreen.main with UIWindowScene lookup
- Add deinit task cancellation in ScheduleViewModel and SuggestedTripsGenerator
- Wrap ~234 unguarded print() calls across 27 files in #if DEBUG

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

SportsTime/Core/Services/DataProvider.swift

@@ -217,7 +217,9 @@ final class AppDataProvider: ObservableObject {
     func filterRichGames(sports: Set<Sport>, startDate: Date, endDate: Date) async throws -> [RichGame] {
         let games = try await filterGames(sports: sports, startDate: startDate, endDate: endDate)
 
+        #if DEBUG
         print("🎮 [DATA] filterRichGames: \(games.count) games from SwiftData for \(sports.map(\.rawValue).joined(separator: ", "))")
+        #endif
 
         var richGames: [RichGame] = []
         var droppedGames: [(game: Game, reason: String)] = []
@@ -243,6 +245,7 @@ final class AppDataProvider: ObservableObject {
             richGames.append(RichGame(game: game, homeTeam: homeTeam!, awayTeam: awayTeam!, stadium: resolvedStadium!))
         }
 
+        #if DEBUG
         if !droppedGames.isEmpty {
             print("⚠️ [DATA] Dropped \(droppedGames.count) games due to missing lookups:")
             for (game, reason) in droppedGames.prefix(10) {
@@ -257,6 +260,7 @@ final class AppDataProvider: ObservableObject {
         }
 
         print("🎮 [DATA] Returning \(richGames.count) rich games")
+        #endif
         return richGames
     }