Add guided reflection flow with mood-adaptive CBT/ACT questions

Walks users through 3-4 guided questions based on mood category:
positive (great/good) gets gratitude-oriented questions, neutral
(average) gets exploratory questions, and negative (bad/horrible)
gets empathetic questions. Stored as JSON in MoodEntryModel,
integrated into PDF reports, AI summaries, and CSV export.

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

Shared/Persisence/DataControllerUPDATE.swift

@@ -51,6 +51,18 @@ extension DataController {
         return true
     }
 
+    // MARK: - Guided Reflection
+
+    @discardableResult
+    func updateReflection(forDate date: Date, reflectionJSON: String?) -> Bool {
+        guard let entry = getEntry(byDate: date) else { return false }
+        entry.reflectionJSON = reflectionJSON
+        saveAndRunDataListeners()
+        let count = reflectionJSON.flatMap { GuidedReflection.decode(from: $0) }?.answeredCount ?? 0
+        AnalyticsManager.shared.track(.reflectionCompleted(answeredCount: count))
+        return true
+    }
+
     // MARK: - Photo
 
     @discardableResult