Fix subscription screen: use product IDs and add close button

- Switch from groupID to productIDs for more reliable product loading
- Add dismiss button overlay so users aren't trapped if products fail to load
- Make productIdentifiers static for shared access

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

Shared/Views/ReflectSubscriptionStoreView.swift

@@ -27,13 +27,25 @@ struct ReflectSubscriptionStoreView: View {
     }
 
     var body: some View {
-        SubscriptionStoreView(groupID: IAPManager.subscriptionGroupID) {
+        SubscriptionStoreView(productIDs: IAPManager.productIdentifiers) {
             marketingContent
         }
         .subscriptionStoreControlStyle(.prominentPicker)
         .storeButton(.visible, for: .restorePurchases)
         .subscriptionStoreButtonLabel(.multiline)
         .tint(tintColor)
+        .overlay(alignment: .topTrailing) {
+            Button {
+                dismiss()
+            } label: {
+                Image(systemName: "xmark.circle.fill")
+                    .font(.title2)
+                    .symbolRenderingMode(.hierarchical)
+                    .foregroundStyle(.secondary)
+            }
+            .padding(16)
+            .accessibilityLabel("Close")
+        }
         .onAppear {
             AnalyticsManager.shared.trackPaywallViewed(source: source)
         }