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/AppDelegate.swift

@@ -24,14 +24,18 @@ class AppDelegate: NSObject, UIApplicationDelegate {
         _ application: UIApplication,
         didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data
     ) {
+        #if DEBUG
         print("📡 [Push] Registered for remote notifications")
+        #endif
     }
 
     func application(
         _ application: UIApplication,
         didFailToRegisterForRemoteNotificationsWithError error: Error
     ) {
+        #if DEBUG
         print("📡 [Push] Failed to register: \(error.localizedDescription)")
+        #endif
     }
 
     func application(