Fix 7 data mutation layer risks identified in audit

- save()/saveAndRunDataListeners() now return @discardableResult Bool;
  listeners only fire on successful save
- MoodLogger.updateMood() now recalculates streak, updates Live Activity,
  and notifies watch (was missing these side effects)
- CSV import uses new addBatch()/importMoods() for O(1) side effects
  instead of O(n) per-row widget reloads and streak calcs
- Foreground task ordering: fillInMissingDates() now runs before
  removeDuplicates() so backfill-created duplicates are caught same cycle
- WidgetMoodSaver deletes ALL entries for date (was fetchLimit=1, leaving
  CloudKit sync duplicates behind)
- cleanupPhotoIfNeeded logs warning on failed photo deletion instead of
  silently orphaning files

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Shared/SharedMoodIntent.swift

@@ -73,15 +73,37 @@ extension VoteMoodIntent: ForegroundContinuableIntent {}
 #if WIDGET_EXTENSION
 enum WidgetMoodSaver {
     private static let logger = Logger(subsystem: "com.tt.feels.widget", category: "WidgetMoodSaver")
+    private static var cachedContainer: ModelContainer?
 
     @MainActor
     static func save(mood: Mood, date: Date) {
+        do {
+            let container = try getOrCreateContainer()
+            try performSave(mood: mood, date: date, container: container)
+        } catch {
+            // Container may be stale or corrupted — discard cache and retry once
+            logger.warning("First save attempt failed, retrying with fresh container: \(error.localizedDescription)")
+            cachedContainer = nil
+            do {
+                let container = try getOrCreateContainer()
+                try performSave(mood: mood, date: date, container: container)
+            } catch {
+                logger.error("Failed to save mood after retry: \(error.localizedDescription)")
+            }
+        }
+    }
+
+    private static func getOrCreateContainer() throws -> ModelContainer {
+        if let existing = cachedContainer {
+            return existing
+        }
+
         let schema = Schema([MoodEntryModel.self])
         let appGroupID = Constants.currentGroupShareId
 
         guard let containerURL = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: appGroupID) else {
             logger.error("App Group not available")
-            return
+            throw WidgetMoodSaverError.appGroupUnavailable
         }
 
         #if DEBUG
@@ -90,34 +112,55 @@ enum WidgetMoodSaver {
         let storeURL = containerURL.appendingPathComponent("Feels.store")
         #endif
 
-        do {
-            let config = ModelConfiguration(schema: schema, url: storeURL, cloudKitDatabase: .none)
-            let container = try ModelContainer(for: schema, configurations: [config])
-            let context = container.mainContext
+        let config = ModelConfiguration(schema: schema, url: storeURL, cloudKitDatabase: .none)
+        let container = try ModelContainer(for: schema, configurations: [config])
+        cachedContainer = container
+        return container
+    }
 
-            // Delete existing entry for this date
-            let startDate = Calendar.current.startOfDay(for: date)
-            let endDate = Calendar.current.date(byAdding: .day, value: 1, to: startDate)!
+    @MainActor
+    private static func performSave(mood: Mood, date: Date, container: ModelContainer) throws {
+        let context = container.mainContext
 
-            var descriptor = FetchDescriptor<MoodEntryModel>(
-                predicate: #Predicate { entry in
-                    entry.forDate >= startDate && entry.forDate <= endDate
-                }
-            )
-            descriptor.fetchLimit = 1
+        // Delete existing entry for this date
+        let startDate = Calendar.current.startOfDay(for: date)
+        let endDate = Calendar.current.date(byAdding: .day, value: 1, to: startDate)!
 
-            if let existing = try? context.fetch(descriptor).first {
-                context.delete(existing)
-                try? context.save()
+        let descriptor = FetchDescriptor<MoodEntryModel>(
+            predicate: #Predicate { entry in
+                entry.forDate >= startDate && entry.forDate < endDate
             }
+        )
 
-            // Create new entry
-            let entry = MoodEntryModel(forDate: date, mood: mood, entryType: .widget)
-            context.insert(entry)
+        let existing = try context.fetch(descriptor)
+        if !existing.isEmpty {
+            for entry in existing {
+                context.delete(entry)
+            }
             try context.save()
-            logger.info("Saved mood \(mood.rawValue) from widget")
-        } catch {
-            logger.error("Failed to save mood: \(error.localizedDescription)")
+        }
+
+        // Create new entry
+        let entry = MoodEntryModel(forDate: date, mood: mood, entryType: .widget)
+        context.insert(entry)
+        try context.save()
+        logger.info("Saved mood \(mood.rawValue) from widget")
+
+        // Note: The widget cannot run full side effects (HealthKit, streaks, analytics, etc.)
+        // because it runs in a separate extension process without access to MoodLogger.
+        // When the main app returns to the foreground, it calls
+        // MoodLogger.shared.processPendingSideEffects() to catch up on any side effects
+        // that were missed from widget or watch entries.
+    }
+
+    enum WidgetMoodSaverError: LocalizedError {
+        case appGroupUnavailable
+
+        var errorDescription: String? {
+            switch self {
+            case .appGroupUnavailable:
+                return "App Group container is not available"
+            }
         }
     }
 }