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/Views/Dashboard/MonthlyCheckInView.swift

@@ -5,13 +5,6 @@ struct MonthlyCheckInView: View {
     @Environment(\.openURL) private var openURL
     @EnvironmentObject var accountStore: AccountStore
     @StateObject private var viewModel = MonthlyCheckInViewModel()
-
-    // Provides the latest snapshot date from CoreData (synced via iCloud) as fallback
-    // for lastCompletionDate when local MonthlyCheckInStore records are stale/missing.
-    @FetchRequest(
-        sortDescriptors: [NSSortDescriptor(keyPath: \Snapshot.date, ascending: false)],
-        animation: .none
-    ) private var latestSnapshots: FetchedResults<Snapshot>
     @State private var referenceDate: Date
 
     @State private var monthlyNote: String
@@ -32,12 +25,7 @@ struct MonthlyCheckInView: View {
     }
 
     private var lastCompletionDate: Date? {
-        // MonthlyCheckInStore lives in UserDefaults (device-local, not iCloud-synced).
-        // On a secondary device after iCloud sync the latest snapshot from CoreData may be
-        // newer than the local check-in record. Use whichever is more recent.
-        let localCompletion = MonthlyCheckInStore.latestCompletionDate()
-        let latestSnapshotDate = latestSnapshots.first?.date
-        return [localCompletion, latestSnapshotDate].compactMap { $0 }.max()
+        MonthlyCheckInStore.latestCompletionDate()
     }
 
     private var checkInProgress: Double {
@@ -162,6 +150,11 @@ struct MonthlyCheckInView: View {
             starRating = MonthlyCheckInStore.rating(for: referenceDate) ?? 0
             selectedMood = MonthlyCheckInStore.mood(for: referenceDate)
         }
+        .onReceive(NotificationCenter.default.publisher(for: .NSManagedObjectContextObjectsDidChange)) { _ in
+            monthlyNote = MonthlyCheckInStore.note(for: referenceDate)
+            starRating = MonthlyCheckInStore.rating(for: referenceDate) ?? 0
+            selectedMood = MonthlyCheckInStore.mood(for: referenceDate)
+        }
         .onReceive(accountStore.$selectedAccount) { account in
             viewModel.selectedAccount = account
             viewModel.selectedRange = DateRange.month(containing: referenceDate)