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/Persisence/SharedModelContainer.swift

@@ -7,14 +7,33 @@
 
 import Foundation
 import SwiftData
+import os.log
+
+/// Errors that can occur when creating the shared model container
+enum SharedModelContainerError: LocalizedError {
+    case appGroupNotAvailable(String)
+    case modelContainerCreationFailed(Error)
+
+    var errorDescription: String? {
+        switch self {
+        case .appGroupNotAvailable(let groupID):
+            return "App Group container not available for: \(groupID)"
+        case .modelContainerCreationFailed(let error):
+            return "Failed to create ModelContainer: \(error.localizedDescription)"
+        }
+    }
+}
 
 enum SharedModelContainer {
+    private static let logger = Logger(subsystem: Bundle.main.bundleIdentifier ?? "com.tt.ifeel", category: "SharedModelContainer")
+
     /// Creates a ModelContainer with the appropriate configuration for app group sharing
     /// - Parameter useCloudKit: Whether to enable CloudKit sync
     /// - Returns: Configured ModelContainer
-    static func create(useCloudKit: Bool = false) -> ModelContainer {
+    /// - Throws: SharedModelContainerError if creation fails
+    static func create(useCloudKit: Bool = false) throws -> ModelContainer {
         let schema = Schema([MoodEntryModel.self])
-        let storeURL = Self.storeURL
+        let storeURL = try Self.storeURL
 
         let configuration: ModelConfiguration
         if useCloudKit {
@@ -36,18 +55,44 @@ enum SharedModelContainer {
         do {
             return try ModelContainer(for: schema, configurations: [configuration])
         } catch {
-            fatalError("Failed to create ModelContainer: \(error)")
+            logger.error("Failed to create ModelContainer: \(error.localizedDescription)")
+            throw SharedModelContainerError.modelContainerCreationFailed(error)
+        }
+    }
+
+    /// Creates a ModelContainer, falling back to in-memory storage if shared container fails
+    /// - Parameter useCloudKit: Whether to enable CloudKit sync
+    /// - Returns: Configured ModelContainer (shared or in-memory fallback)
+    static func createWithFallback(useCloudKit: Bool = false) -> ModelContainer {
+        do {
+            return try create(useCloudKit: useCloudKit)
+        } catch {
+            logger.warning("Falling back to in-memory storage due to: \(error.localizedDescription)")
+            // Fall back to in-memory storage
+            let schema = Schema([MoodEntryModel.self])
+            let config = ModelConfiguration(schema: schema, isStoredInMemoryOnly: true)
+            do {
+                return try ModelContainer(for: schema, configurations: [config])
+            } catch {
+                // This should never happen with in-memory storage, but handle it gracefully
+                logger.critical("Failed to create even in-memory ModelContainer: \(error.localizedDescription)")
+                preconditionFailure("Unable to create ModelContainer: \(error)")
+            }
         }
     }
 
     /// The URL for the SwiftData store in the shared app group container
+    /// - Throws: SharedModelContainerError if app group is not available
     static var storeURL: URL {
-        guard let containerURL = FileManager.default.containerURL(
-            forSecurityApplicationGroupIdentifier: appGroupID
-        ) else {
-            fatalError("App Group container not available for: \(appGroupID)")
+        get throws {
+            guard let containerURL = FileManager.default.containerURL(
+                forSecurityApplicationGroupIdentifier: appGroupID
+            ) else {
+                logger.error("App Group container not available for: \(appGroupID)")
+                throw SharedModelContainerError.appGroupNotAvailable(appGroupID)
+            }
+            return containerURL.appendingPathComponent(storeFileName)
         }
-        return containerURL.appendingPathComponent(storeFileName)
     }
 
     /// App Group identifier based on build configuration