Refactor StoreKit 2 subscription system and add interactive vote widget

## StoreKit 2 Refactor
- Rewrote IAPManager with clean enum-based state model (SubscriptionState)
- Added native SubscriptionStoreView for iOS 17+ purchase UI
- Subscription status now checked on every app launch
- Synced subscription status to UserDefaults for widget access
- Simplified PurchaseButtonView and IAPWarningView
- Removed unused StatusInfoView

## Interactive Vote Widget
- New FeelsVoteWidget with App Intents for mood voting
- Subscribers can vote directly from widget, shows stats after voting
- Non-subscribers see "Tap to subscribe" which opens subscription store
- Added feels:// URL scheme for deep linking

## Firebase Removal
- Commented out Firebase imports and initialization
- EventLogger now prints to console in DEBUG mode only

## Other Changes
- Added fallback for Core Data when App Group unavailable
- Added new localization strings for subscription UI
- Updated entitlements and Info.plist

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

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

Shared/views/MonthView/MonthView.swift

@@ -44,8 +44,9 @@ struct MonthView: View {
     ]
     
     @ObservedObject var viewModel: DayViewViewModel
-    @State private var iAPWarningViewHidden = false
-    
+    @State private var trialWarningHidden = false
+    @State private var showSubscriptionStore = false
+
     var body: some View {
         ZStack {
             if viewModel.hasNoData {
@@ -55,7 +56,7 @@ struct MonthView: View {
                 ScrollView {
                     VStack(spacing: 5) {
                         ForEach(viewModel.grouped.sorted(by: { $0.key < $1.key }), id: \.key) { year, months in
-                            
+
                             // for reach month
                             ForEach(months.sorted(by: { $0.key < $1.key }), id: \.key) { month, entries in
                                 Section() {
@@ -80,23 +81,43 @@ struct MonthView: View {
                         }
                     )
                 }
-                .disabled(iapManager.showIAP)
+                .disabled(iapManager.shouldShowPaywall)
             }
-            
-            if iapManager.showIAP {
+
+            if iapManager.shouldShowPaywall {
+                // Paywall overlay - tap to show subscription store
+                Color.black.opacity(0.3)
+                    .ignoresSafeArea()
+                    .onTapGesture {
+                        showSubscriptionStore = true
+                    }
+
                 VStack {
                     Spacer()
-                    PurchaseButtonView(height: 250, iapManager: iapManager)
+                    Button {
+                        showSubscriptionStore = true
+                    } label: {
+                        Text(String(localized: "subscription_required_button"))
+                            .font(.headline)
+                            .foregroundColor(.white)
+                            .frame(maxWidth: .infinity)
+                            .padding()
+                            .background(RoundedRectangle(cornerRadius: 10).fill(Color.pink))
+                    }
+                    .padding()
                 }
-            } else if iapManager.showIAPWarning {
+            } else if iapManager.shouldShowTrialWarning {
                 VStack {
                     Spacer()
-                    if !iAPWarningViewHidden {
-                        IAPWarningView(height: 75, iapManager: iapManager)
+                    if !trialWarningHidden {
+                        IAPWarningView(iapManager: iapManager)
                     }
                 }
             }
         }
+        .sheet(isPresented: $showSubscriptionStore) {
+            FeelsSubscriptionStoreView()
+        }
         .onAppear(perform: {
             EventLogger.log(event: "show_month_view")
         })
@@ -116,7 +137,7 @@ struct MonthView: View {
         }
         .onPreferenceChange(ViewOffsetKey.self) { value in
             withAnimation {
-                iAPWarningViewHidden = value < 0
+                trialWarningHidden = value < 0
             }
         }
     }