Migrate journal entries to CoreData for iCloud sync (build 33)

- Add JournalEntry CoreData entity (syncable=YES): id, monthKey, note, moodRaw, rating, completionTime, createdAt
- Rewrite MonthlyCheckInStore: CoreData as primary storage, same public API
- One-time migration from UserDefaults triggered after store loads
- MonthlyCheckInCard: @FetchRequest on JournalEntry — reactive to iCloud sync
- MonthlyCheckInView: onReceive NSManagedObjectContextObjectsDidChange to refresh @State vars on sync
- Stats cards: observe NSManagedObjectContextObjectsDidChange instead of UserDefaults
- ChartsViewModel.completedMonthKeys: remove MonthlyCheckInStore dependency (data-driven)

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

PortfolioJournal/Models/CoreData/JournalEntry+CoreDataClass.swift

@@ -0,0 +1,38 @@
+import Foundation
+import CoreData
+
+@objc(JournalEntry)
+public class JournalEntry: NSManagedObject, Identifiable {
+    @nonobjc public class func fetchRequest() -> NSFetchRequest<JournalEntry> {
+        return NSFetchRequest<JournalEntry>(entityName: "JournalEntry")
+    }
+
+    @NSManaged public var id: UUID?
+    @NSManaged public var monthKey: String?
+    @NSManaged public var note: String?
+    @NSManaged public var moodRaw: String?
+    @NSManaged public var rating: Int16
+    @NSManaged public var completionTime: Date?
+    @NSManaged public var createdAt: Date?
+
+    public override func awakeFromInsert() {
+        super.awakeFromInsert()
+        id = UUID()
+        createdAt = Date()
+    }
+
+    var mood: MonthlyCheckInMood? {
+        get { moodRaw.flatMap { MonthlyCheckInMood(rawValue: $0) } }
+        set { moodRaw = newValue?.rawValue }
+    }
+
+    var ratingValue: Int? {
+        get { rating > 0 ? Int(rating) : nil }
+        set { rating = Int16(newValue.map { min(max(1, $0), 5) } ?? 0) }
+    }
+
+    var completionDate: Date? {
+        get { completionTime }
+        set { completionTime = newValue }
+    }
+}

PortfolioJournal/Models/CoreData/PortfolioJournal.xcdatamodeld/PortfolioJournal.xcdatamodel/contents

@@ -102,4 +102,13 @@
         <attribute name="value" optional="YES" attributeType="Decimal"/>
         <relationship name="source" optional="YES" maxCount="1" deletionRule="Nullify" destinationEntity="InvestmentSource" inverseName="snapshots" inverseEntity="InvestmentSource"/>
     </entity>
+    <entity name="JournalEntry" representedClassName="JournalEntry" syncable="YES">
+        <attribute name="id" optional="YES" attributeType="UUID" usesScalarValueType="NO"/>
+        <attribute name="monthKey" optional="YES" attributeType="String"/>
+        <attribute name="note" optional="YES" attributeType="String"/>
+        <attribute name="moodRaw" optional="YES" attributeType="String"/>
+        <attribute name="rating" optional="YES" attributeType="Integer 16" usesScalarValueType="YES"/>
+        <attribute name="completionTime" optional="YES" attributeType="Date" usesScalarValueType="NO"/>
+        <attribute name="createdAt" optional="YES" attributeType="Date" usesScalarValueType="NO"/>
+    </entity>
 </model>

PortfolioJournal/Models/CoreDataStack.swift

@@ -186,6 +186,7 @@ class CoreDataStack: ObservableObject {
             }
             DispatchQueue.main.async {
                 self?.isLoaded = true
+                MonthlyCheckInStore.migrateIfNeeded()
             }
         }