Migrate from Core Data to SwiftData

- Replace Core Data with SwiftData for iOS 18+
- Create MoodEntryModel as @Model class replacing MoodEntry entity
- Create SharedModelContainer for App Group container sharing
- Create DataController with CRUD extensions replacing PersistenceController
- Update all views and view models to use MoodEntryModel
- Update widget extension to use SwiftData
- Remove old Core Data files (Persistence*.swift, .xcdatamodeld)
- Add EntryType enum with all entry type cases
- Fix widget label truncation with proper spacing and text scaling

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Shared/Views/EntryListView.swift

@@ -13,7 +13,7 @@ struct EntryListView: View {
     @AppStorage(UserDefaultsStore.Keys.textColor.rawValue, store: GroupUserDefaults.groupDefaults) private var textColor: Color = DefaultTextColor.textColor
     @Environment(\.colorScheme) private var colorScheme
 
-    public let entry: MoodEntry
+    public let entry: MoodEntryModel
 
     private var moodColor: Color {
         moodTint.color(forMood: entry.mood)
@@ -53,14 +53,14 @@ struct EntryListView: View {
             VStack(alignment: .leading, spacing: 6) {
                 // Date row
                 HStack(spacing: 6) {
-                    Text(Random.weekdayName(fromDate: entry.forDate!))
+                    Text(Random.weekdayName(fromDate: entry.forDate))
                         .font(.system(size: 17, weight: .semibold))
                         .foregroundColor(textColor)
 
                     Text("•")
                         .foregroundColor(textColor.opacity(0.4))
 
-                    Text(Random.dayFormat(fromDate: entry.forDate!))
+                    Text(Random.dayFormat(fromDate: entry.forDate))
                         .font(.system(size: 17, weight: .medium))
                         .foregroundColor(textColor.opacity(0.8))
                 }
@@ -115,7 +115,7 @@ struct EntryListView: View {
 }
 
 struct EntryListView_Previews: PreviewProvider {
-    static let fakeData = PersistenceController.shared.randomEntries(count: 1).first!
+    @MainActor static let fakeData = DataController.shared.randomEntries(count: 1).first!
 
     static var previews: some View {
         VStack(spacing: 8) {