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/Persisence/Persistence.swift

@@ -9,12 +9,14 @@ import CoreData
 import SwiftUI
 
 class PersistenceController {
-    @AppStorage(UserDefaultsStore.Keys.useCloudKit.rawValue, store: GroupUserDefaults.groupDefaults) private var useCloudKit = false
+    @AppStorage(UserDefaultsStore.Keys.useCloudKit.rawValue, store: GroupUserDefaults.groupDefaults)
+    
+    private var useCloudKit = false
     
     static let shared = PersistenceController.persistenceController
         
     private static var persistenceController: PersistenceController {
-        return PersistenceController(inMemory: false)
+        return PersistenceController(inMemory: true)
     }
     
     public var viewContext: NSManagedObjectContext {
@@ -117,12 +119,19 @@ extension NSManagedObjectContext {
 class NSCustomPersistentContainer: NSPersistentContainer {
     override open class func defaultDirectoryURL() -> URL {
 #if DEBUG
-        var storeURLDebug = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: Constants.groupShareIdDebug)
-        storeURLDebug = storeURLDebug?.appendingPathComponent("Feels-Debug.sqlite")
-        return storeURLDebug!
+        if let storeURLDebug = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: Constants.groupShareIdDebug) {
+            return storeURLDebug.appendingPathComponent("Feels-Debug.sqlite")
+        }
+        // Fallback to default location if App Group not available
+        print("⚠️ App Group not available, using default Core Data location")
+        return super.defaultDirectoryURL()
+#else
+        if let storeURL = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: Constants.groupShareId) {
+            return storeURL.appendingPathComponent("Feels.sqlite")
+        }
+        // Fallback to default location if App Group not available
+        print("⚠️ App Group not available, using default Core Data location")
+        return super.defaultDirectoryURL()
 #endif
-        var storeURL = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: Constants.groupShareId)
-        storeURL = storeURL?.appendingPathComponent("Feels.sqlite")
-        return storeURL!
     }
 }