fix: 14 audit fixes — concurrency, memory, performance, accessibility

Second audit round addressing data races, task stacking, unbounded
caches, and VoiceOver gaps across 7 files.

Concurrency:
- Move NSItemProvider @State access into MainActor block (3 drop handlers)
- Cancel stale ScheduleViewModel tasks on rapid filter changes

Memory:
- Replace unbounded image dict with LRUCache(countLimit: 50)
- Replace demo-mode asyncAfter with cancellable Task

Performance:
- Wrap debug NBA print() in #if DEBUG
- Cache visitsById via @State + onChange instead of per-render computed
- Pre-compute sportProgressFractions in ProgressViewModel
- Replace allGames computed property with hasGames bool check
- Cache sortedTrips via @State + onChange in SavedTripsListView

Accessibility:
- Add combined VoiceOver label to progress ring
- Combine away/home team text into single readable phrase
- Hide decorative StadiumDetailSheet icon from VoiceOver
- Add explicit accessibilityLabel to SportFilterChip
- Add combined accessibilityLabel to GameRowView

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

SportsTime/Features/Progress/Views/ProgressTabView.swift

@@ -19,11 +19,7 @@ struct ProgressTabView: View {
     @State private var selectedVisitId: UUID?
 
     @Query private var visits: [StadiumVisit]
-
-    /// O(1) lookup for visits by ID (built from @Query results)
-    private var visitsById: [UUID: StadiumVisit] {
-        Dictionary(uniqueKeysWithValues: visits.map { ($0.id, $0) })
-    }
+    @State private var visitsById: [UUID: StadiumVisit] = [:]
 
     var body: some View {
         Group {
@@ -66,6 +62,9 @@ struct ProgressTabView: View {
                 .accessibilityLabel("Add stadium visit")
             }
         }
+        .onChange(of: visits, initial: true) { _, newVisits in
+            visitsById = Dictionary(uniqueKeysWithValues: newVisits.map { ($0.id, $0) })
+        }
         .task {
             viewModel.configure(with: modelContext.container)
             await viewModel.loadData()
@@ -153,7 +152,7 @@ struct ProgressTabView: View {
             SportProgressButton(
                 sport: sport,
                 isSelected: viewModel.selectedSport == sport,
-                progress: progressForSport(sport)
+                progress: viewModel.sportProgressFractions[sport] ?? 0
             ) {
                 Theme.Animation.withMotion(Theme.Animation.spring) {
                     viewModel.selectSport(sport)
@@ -162,12 +161,6 @@ struct ProgressTabView: View {
         }
     }
 
-    private func progressForSport(_ sport: Sport) -> Double {
-        let visitedCount = viewModel.visits.filter { $0.sportEnum == sport }.count
-        let total = LeagueStructure.stadiumCount(for: sport)
-        guard total > 0 else { return 0 }
-        return Double(min(visitedCount, total)) / Double(total)
-    }
 
     // MARK: - Progress Summary Card
 
@@ -204,6 +197,8 @@ struct ProgressTabView: View {
                             .foregroundStyle(Theme.textMuted(colorScheme))
                     }
                 }
+                .accessibilityElement(children: .ignore)
+                .accessibilityLabel("\(progress.visitedStadiums) of \(progress.totalStadiums) stadiums visited, \(Int(progress.completionPercentage)) percent complete")
 
                 VStack(alignment: .leading, spacing: Theme.Spacing.xs) {
                     Text(viewModel.selectedSport.displayName)
@@ -540,13 +535,10 @@ struct RecentVisitRow: View {
                     .font(.body)
                     .foregroundStyle(Theme.textPrimary(colorScheme))
 
-                // Date, Away @ Home on one line, left aligned
                 VStack(alignment: .leading, spacing: 4) {
                     Text(visit.shortDateDescription)
                     if let away = visit.awayTeamName, let home = visit.homeTeamName {
-                        Text(away)
-                        Text("@")
-                        Text(home)
+                        Text("\(away) at \(home)")
                     }
                 }
                 .font(.subheadline)
@@ -596,6 +588,7 @@ struct StadiumDetailSheet: View {
                             .font(.largeTitle)
                             .foregroundStyle(visitStatus.isVisited ? .green : sport.themeColor)
                     }
+                    .accessibilityHidden(true)
 
                     Text(stadium.name)
                         .font(.headline)