Fix build errors, resolve all warnings, and improve code quality

Widget Extension Fixes:
- Create standalone WidgetDataProvider for widget data isolation
- Add WIDGET_EXTENSION compiler flag for conditional compilation
- Fix DataController references in widget-shared files
- Sync widget version numbers with main app (23, 1.0.2)
- Add WidgetBackground color to asset catalog

Warning Resolutions:
- Fix UIScreen.main deprecation in BGView and SharingListView
- Fix Text '+' concatenation deprecation in PurchaseButtonView and SettingsTabView
- Fix exhaustive switch in BiometricAuthManager (add .none case)
- Fix var to let in ExportService (3 instances)
- Fix unused result warning in NoteEditorView
- Fix ForEach duplicate ID warnings in MonthView and YearView

Code Quality Improvements:
- Wrap bypassSubscription in #if DEBUG for security
- Rename StupidAssCustomWidgetObservableObject to CustomWidgetStateViewModel
- Add @MainActor to IconViewModel
- Replace fatalError with graceful fallback in SharedModelContainer
- Add [weak self] to closures in DayViewViewModel
- Add OSLog-based AppLogger for production logging
- Add ImageCache with NSCache for memory efficiency
- Add AccessibilityHelpers with Reduce Motion support
- Create DataControllerProtocol for dependency injection
- Update .gitignore with secrets exclusions

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

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

FeelsWidget2/FeelsWidget.swift

@@ -157,13 +157,16 @@ struct TimeLineCreator {
            Calendar.current.date(byAdding: .day, value: -$0, to: latestDayToShow)!
         })
 
+        // Use WidgetDataProvider for isolated widget data access
+        let dataProvider = WidgetDataProvider.shared
+
         for date in dates {
             let dayStart = Calendar.current.startOfDay(for: date)
             let dayEnd = Calendar.current.date(bySettingHour: 23, minute: 59, second: 59, of: dayStart)!
             let moodTint: MoodTintable.Type = UserDefaultsStore.moodTintable()
             let moodImages: MoodImagable.Type = UserDefaultsStore.moodMoodImagable()
 
-            if let todayEntry = DataController.shared.getData(startDate: dayStart, endDate: dayEnd, includedDays: []).first {
+            if let todayEntry = dataProvider.getData(startDate: dayStart, endDate: dayEnd, includedDays: []).first {
                 timeLineView.append(WatchTimelineView(image: moodImages.icon(forMood: todayEntry.mood),
                                                       graphic: moodImages.icon(forMood: todayEntry.mood),
                                                       date: dayStart,
@@ -267,7 +270,8 @@ struct Provider: @preconcurrency IntentTimelineProvider {
         let dayStart = Calendar.current.startOfDay(for: votingDate)
         let dayEnd = Calendar.current.date(bySettingHour: 23, minute: 59, second: 59, of: dayStart) ?? dayStart
 
-        let todayEntry = DataController.shared.getData(startDate: dayStart, endDate: dayEnd, includedDays: []).first
+        // Use WidgetDataProvider for isolated widget data access
+        let todayEntry = WidgetDataProvider.shared.getData(startDate: dayStart, endDate: dayEnd, includedDays: []).first
         let hasVotedToday = todayEntry != nil && todayEntry?.mood != Mood.missing && todayEntry?.mood != Mood.placeholder
 
         let promptText = UserDefaultsStore.personalityPackable().randomPushNotificationStrings().body