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/Persisence/DataControllerGET.swift

@@ -0,0 +1,85 @@
+//
+//  DataControllerGET.swift
+//  Feels
+//
+//  SwiftData READ operations.
+//
+
+import SwiftData
+import Foundation
+
+extension DataController {
+    func getEntry(byDate date: Date) -> MoodEntryModel? {
+        let startDate = Calendar.current.startOfDay(for: date)
+        let endDate = Calendar.current.date(byAdding: .day, value: 1, to: startDate)!
+
+        var descriptor = FetchDescriptor<MoodEntryModel>(
+            predicate: #Predicate { entry in
+                entry.forDate >= startDate && entry.forDate <= endDate
+            },
+            sortBy: [SortDescriptor(\.forDate, order: .forward)]
+        )
+        descriptor.fetchLimit = 1
+
+        return try? modelContext.fetch(descriptor).first
+    }
+
+    func getData(startDate: Date, endDate: Date, includedDays: [Int]) -> [MoodEntryModel] {
+        let weekDays = includedDays.isEmpty ? [1, 2, 3, 4, 5, 6, 7] : includedDays
+
+        let descriptor = FetchDescriptor<MoodEntryModel>(
+            predicate: #Predicate { entry in
+                entry.forDate >= startDate &&
+                entry.forDate <= endDate &&
+                weekDays.contains(entry.weekDay)
+            },
+            sortBy: [SortDescriptor(\.forDate, order: .forward)]
+        )
+
+        return (try? modelContext.fetch(descriptor)) ?? []
+    }
+
+    func splitIntoYearMonth(includedDays: [Int]) -> [Int: [Int: [MoodEntryModel]]] {
+        let data = getData(
+            startDate: Date(timeIntervalSince1970: 0),
+            endDate: Date(),
+            includedDays: includedDays
+        ).sorted { $0.forDate < $1.forDate }
+
+        guard let earliest = data.first,
+              let latest = data.last else { return [:] }
+
+        let calendar = Calendar.current
+        let earliestYear = calendar.component(.year, from: earliest.forDate)
+        let latestYear = calendar.component(.year, from: latest.forDate)
+
+        var result = [Int: [Int: [MoodEntryModel]]]()
+
+        for year in earliestYear...latestYear {
+            var monthData = [Int: [MoodEntryModel]]()
+
+            for month in 1...12 {
+                var components = DateComponents()
+                components.year = year
+                components.month = month
+                components.day = 1
+
+                guard let startOfMonth = calendar.date(from: components) else { continue }
+
+                let items = getData(
+                    startDate: startOfMonth,
+                    endDate: startOfMonth.endOfMonth,
+                    includedDays: [1, 2, 3, 4, 5, 6, 7]
+                )
+
+                if !items.isEmpty {
+                    monthData[month] = items
+                }
+            }
+
+            result[year] = monthData
+        }
+
+        return result
+    }
+}