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/YearView/YearView.swift

@@ -6,17 +6,15 @@
 //
 
 import SwiftUI
-import CoreData
+import SwiftData
 
 struct YearView: View {
     let months = [(0, "J"), (1, "F"), (2,"M"), (3,"A"), (4,"M"), (5, "J"), (6,"J"), (7,"A"), (8,"S"), (9,"O"), (10, "N"), (11,"D")]
 
     @State private var toggle = true
 
-    @FetchRequest(
-        sortDescriptors: [NSSortDescriptor(keyPath: \MoodEntry.forDate, ascending: false)],
-        animation: .spring())
-    private var items: FetchedResults<MoodEntry>
+    @Query(sort: \MoodEntryModel.forDate, order: .reverse)
+    private var items: [MoodEntryModel]
 
     @AppStorage(UserDefaultsStore.Keys.theme.rawValue, store: GroupUserDefaults.groupDefaults) private var theme: Theme = .system
     @AppStorage(UserDefaultsStore.Keys.moodTint.rawValue, store: GroupUserDefaults.groupDefaults) private var moodTint: MoodTints = .Default
@@ -128,10 +126,10 @@ struct YearCard: View {
     private let months = ["J", "F", "M", "A", "M", "J", "J", "A", "S", "O", "N", "D"]
     private let heatmapColumns = Array(repeating: GridItem(.flexible(), spacing: 2), count: 12)
 
-    private var yearEntries: [MoodEntry] {
+    private var yearEntries: [MoodEntryModel] {
         let firstOfYear = Calendar.current.date(from: DateComponents(year: year, month: 1, day: 1))!
         let lastOfYear = Calendar.current.date(from: DateComponents(year: year + 1, month: 1, day: 1))!
-        return PersistenceController.shared.getData(startDate: firstOfYear, endDate: lastOfYear, includedDays: filteredDays)
+        return DataController.shared.getData(startDate: firstOfYear, endDate: lastOfYear, includedDays: filteredDays)
     }
 
     private var metrics: [MoodMetrics] {