Add premium features and reorganize Settings tab

Premium Features:
- Journal notes and photo attachments for mood entries
- Data export (CSV and PDF reports)
- Privacy lock with Face ID/Touch ID
- Apple Health integration for mood correlation
- 4 new personality packs (Motivational Coach, Zen Master, Best Friend, Data Analyst)

Settings Tab Reorganization:
- Combined Customize and Settings into single tab with segmented control
- Added upgrade banner with trial countdown above segment
- "Why Upgrade?" sheet showing all premium benefits
- Subscribe button opens improved StoreKit 2 subscription view

UI Improvements:
- Enhanced subscription store with feature highlights
- Entry detail view for viewing/editing notes and photos
- Removed duplicate subscription banners from tab content

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Shared/FeelsApp.swift

@@ -17,6 +17,7 @@ struct FeelsApp: App {
 
     let dataController = DataController.shared
     @StateObject var iapManager = IAPManager()
+    @StateObject var authManager = BiometricAuthManager()
     @AppStorage(UserDefaultsStore.Keys.firstLaunchDate.rawValue, store: GroupUserDefaults.groupDefaults) private var firstLaunchDate = Date()
     @State private var showSubscriptionFromWidget = false
 
@@ -30,26 +31,36 @@ struct FeelsApp: App {
 
     var body: some Scene {
         WindowGroup {
-            MainTabView(dayView: DayView(viewModel: DayViewViewModel(addMonthStartWeekdayPadding: false)),
-                        monthView: MonthView(viewModel: DayViewViewModel(addMonthStartWeekdayPadding: true)),
-                        yearView: YearView(viewModel: YearViewModel()),
-                        insightsView: InsightsView(),
-                        customizeView: CustomizeView())
-            .modelContainer(dataController.container)
-            .environmentObject(iapManager)
-            .sheet(isPresented: $showSubscriptionFromWidget) {
-                FeelsSubscriptionStoreView()
-                    .environmentObject(iapManager)
-            }
-            .onOpenURL { url in
-                if url.scheme == "feels" && url.host == "subscribe" {
-                    showSubscriptionFromWidget = true
+            ZStack {
+                MainTabView(dayView: DayView(viewModel: DayViewViewModel(addMonthStartWeekdayPadding: false)),
+                            monthView: MonthView(viewModel: DayViewViewModel(addMonthStartWeekdayPadding: true)),
+                            yearView: YearView(viewModel: YearViewModel()),
+                            insightsView: InsightsView())
+                .modelContainer(dataController.container)
+                .environmentObject(iapManager)
+                .environmentObject(authManager)
+                .sheet(isPresented: $showSubscriptionFromWidget) {
+                    FeelsSubscriptionStoreView()
+                        .environmentObject(iapManager)
+                }
+                .onOpenURL { url in
+                    if url.scheme == "feels" && url.host == "subscribe" {
+                        showSubscriptionFromWidget = true
+                    }
+                }
+
+                // Lock screen overlay
+                if authManager.isLockEnabled && !authManager.isUnlocked {
+                    LockScreenView(authManager: authManager)
+                        .transition(.opacity)
                 }
             }
         }.onChange(of: scenePhase) { _, newPhase in
             if newPhase == .background {
                 //BGTask.scheduleBackgroundProcessing()
                 WidgetCenter.shared.reloadAllTimelines()
+                // Lock the app when going to background
+                authManager.lock()
             }
 
             if newPhase == .active {
@@ -58,6 +69,12 @@ struct FeelsApp: App {
                 Task {
                     await iapManager.checkSubscriptionStatus()
                 }
+                // Authenticate if locked
+                if authManager.isLockEnabled && !authManager.isUnlocked {
+                    Task {
+                        await authManager.authenticate()
+                    }
+                }
             }
         }
     }