feat(store): add In-App Purchase system with Pro subscription

Implement freemium model with StoreKit 2:
- StoreManager singleton for purchase/restore/entitlements
- ProFeature enum defining gated features
- PaywallView and OnboardingPaywallView for upsell UI
- ProGate view modifier and ProBadge component

Feature gating:
- Trip saving: 1 free trip, then requires Pro
- PDF export: Pro only with badge indicator
- Progress tab: Shows ProLockedView for free users
- Settings: Subscription management section

Also fixes pre-existing test issues with StadiumVisit
and ItineraryOption model signature changes.

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

SportsTime/Features/Home/Views/HomeView.swift

@@ -17,6 +17,7 @@ struct HomeView: View {
     @State private var suggestedTripsGenerator = SuggestedTripsGenerator()
     @State private var selectedSuggestedTrip: SuggestedTrip?
     @State private var displayedTips: [PlanningTip] = []
+    @State private var showProPaywall = false
 
     var body: some View {
         TabView(selection: $selectedTab) {
@@ -86,7 +87,13 @@ struct HomeView: View {
 
             // Progress Tab
             NavigationStack {
-                ProgressTabView()
+                if StoreManager.shared.isPro {
+                    ProgressTabView()
+                } else {
+                    ProLockedView(feature: .progressTracking) {
+                        showProPaywall = true
+                    }
+                }
             }
             .tabItem {
                 Label("Progress", systemImage: "chart.bar.fill")
@@ -121,6 +128,9 @@ struct HomeView: View {
                 TripDetailView(trip: suggestedTrip.trip, games: suggestedTrip.richGames)
             }
         }
+        .sheet(isPresented: $showProPaywall) {
+            PaywallView()
+        }
     }
 
     // MARK: - Hero Card
@@ -548,6 +558,63 @@ struct SavedTripListRow: View {
     }
 }
 
+// MARK: - Pro Locked View
+
+struct ProLockedView: View {
+    let feature: ProFeature
+    let onUnlock: () -> Void
+
+    @Environment(\.colorScheme) private var colorScheme
+
+    var body: some View {
+        VStack(spacing: Theme.Spacing.xl) {
+            Spacer()
+
+            ZStack {
+                Circle()
+                    .fill(Theme.warmOrange.opacity(0.15))
+                    .frame(width: 100, height: 100)
+
+                Image(systemName: "lock.fill")
+                    .font(.system(size: 40))
+                    .foregroundStyle(Theme.warmOrange)
+            }
+
+            VStack(spacing: Theme.Spacing.sm) {
+                Text(feature.displayName)
+                    .font(.title2.bold())
+                    .foregroundStyle(Theme.textPrimary(colorScheme))
+
+                Text(feature.description)
+                    .font(.body)
+                    .foregroundStyle(Theme.textSecondary(colorScheme))
+                    .multilineTextAlignment(.center)
+                    .padding(.horizontal, Theme.Spacing.xl)
+            }
+
+            Button {
+                onUnlock()
+            } label: {
+                HStack {
+                    Image(systemName: "star.fill")
+                    Text("Upgrade to Pro")
+                }
+                .fontWeight(.semibold)
+                .frame(maxWidth: .infinity)
+                .padding(Theme.Spacing.md)
+                .background(Theme.warmOrange)
+                .foregroundStyle(.white)
+                .clipShape(RoundedRectangle(cornerRadius: Theme.CornerRadius.medium))
+            }
+            .padding(.horizontal, Theme.Spacing.xl)
+
+            Spacer()
+            Spacer()
+        }
+        .themedBackground()
+    }
+}
+
 #Preview {
     HomeView()
         .modelContainer(for: SavedTrip.self, inMemory: true)