Xcode 27: compila sin warnings y migra API deprecadas de SwiftUI

- Imports de CoreData que faltaban (MemberImportVisibility) en AccountsView,
  ImportDataView, ChartsContainerView y AddSourceView.
- Aislamiento MainActor: IsolatedDefaultValues en el target de la app,
  LinearGradient @MainActor, WatchSyncMessage nonisolated, closures de
  ReviewPromptService/MonthlyCheckInStore/AppIntents.
- Warnings de valores sin usar (SnapshotGapDetector, DashboardLayoutStore,
  OnboardingView, GoalEditorView, CoreDataStack, SettingsViewModel).
- foregroundColor→foregroundStyle, cornerRadius→clipShape,
  navigationBarLeading/Trailing→topBarLeading/Trailing,
  Task.sleep(nanoseconds:)→sleep(for:), NavigationLink(isActive:)→
  navigationDestination(isPresented:).

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01F1u4K16xy7eQVtgsYNZ9Vn

PortfolioJournal/Utilities/MonthlyCheckInStore.swift

@@ -66,7 +66,7 @@ enum MonthlyCheckInStore {
     }
 
     static func entry(for date: Date) -> MonthlyCheckInEntry? {
-        fetchEntry(for: monthKey(for: date)).map(makeCheckInEntry)
+        fetchEntry(for: monthKey(for: date)).map { makeCheckInEntry($0) }
     }
 
     static func allEntries() -> [(date: Date, entry: MonthlyCheckInEntry)] {