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>

macOS/macOS.entitlements

@@ -1,10 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
-<dict>
-    <key>com.apple.security.app-sandbox</key>
-    <true/>
-    <key>com.apple.security.files.user-selected.read-only</key>
-    <true/>
-</dict>
+<dict/>
 </plist>