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/EventLogger.swift

@@ -6,10 +6,14 @@
 //
 
 import Foundation
-import Firebase
+// import Firebase  // Firebase removed
 
 class EventLogger {
     static func log(event: String, withData data: [String: Any]? = nil) {
-        Analytics.logEvent(event, parameters: data)
+        // Firebase Analytics disabled
+        // Analytics.logEvent(event, parameters: data)
+        #if DEBUG
+        print("[EventLogger] \(event)", data ?? "")
+        #endif
     }
 }