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/Features/Trip/Views/ItineraryTableViewController.swift

@@ -869,6 +869,7 @@ final class ItineraryTableViewController: UITableViewController {
             let sortOrder = calculateSortOrder(at: destinationIndexPath.row)
             
             // DEBUG: Log the final state after insertion
+            #if DEBUG
             print("🎯 [Drop] source=\(sourceIndexPath.row) → dest=\(destinationIndexPath.row)")
             print("🎯 [Drop] flatItems around dest:")
             for i in max(0, destinationIndexPath.row - 2)...min(flatItems.count - 1, destinationIndexPath.row + 2) {
@@ -876,6 +877,7 @@ final class ItineraryTableViewController: UITableViewController {
                 print("🎯 [Drop] \(marker) [\(i)] \(flatItems[i])")
             }
             print("🎯 [Drop] Calculated day=\(destinationDay), sortOrder=\(sortOrder)")
+            #endif
             
             onCustomItemMoved?(customItem.id, destinationDay, sortOrder)