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>

Shared/Services/AppLogger.swift

@@ -0,0 +1,34 @@
+//
+//  AppLogger.swift
+//  Feels
+//
+//  Centralized logging using OSLog for production-ready logging.
+//
+
+import Foundation
+import os.log
+
+/// Centralized logging utility using OSLog
+enum AppLogger {
+    // MARK: - Loggers by Category
+
+    static let general = Logger(subsystem: subsystem, category: "General")
+    static let iap = Logger(subsystem: subsystem, category: "IAP")
+    static let healthKit = Logger(subsystem: subsystem, category: "HealthKit")
+    static let liveActivity = Logger(subsystem: subsystem, category: "LiveActivity")
+    static let notifications = Logger(subsystem: subsystem, category: "Notifications")
+    static let photos = Logger(subsystem: subsystem, category: "Photos")
+    static let export = Logger(subsystem: subsystem, category: "Export")
+    static let settings = Logger(subsystem: subsystem, category: "Settings")
+    static let biometrics = Logger(subsystem: subsystem, category: "Biometrics")
+    static let ai = Logger(subsystem: subsystem, category: "AI")
+    static let events = Logger(subsystem: subsystem, category: "Events")
+    static let userDefaults = Logger(subsystem: subsystem, category: "UserDefaults")
+    static let backgroundTasks = Logger(subsystem: subsystem, category: "BackgroundTasks")
+
+    // MARK: - Private
+
+    private static var subsystem: String {
+        Bundle.main.bundleIdentifier ?? "com.tt.ifeel"
+    }
+}