Add CoreData-based workout tracking app with iOS and watchOS targets

- Migrate from SwiftData to CoreData with CloudKit sync
- Add core models: Split, Exercise, Workout, WorkoutLog
- Implement tab-based UI: Workout Logs, Splits, Settings
- Add SF Symbols picker for split icons
- Add exercise picker filtered by split with exclusion of added exercises
- Integrate IndieAbout for settings/about section
- Add Yams for YAML exercise definition parsing
- Include starter exercise libraries (bodyweight, Planet Fitness)
- Add Date extensions for formatting (formattedTime, isSameDay)
- Format workout date ranges to show time-only for same-day end dates
- Add build number update script
- Add app icons

Workouts/Persistence/PersistenceController.swift

@@ -0,0 +1,119 @@
+import CoreData
+import CloudKit
+
+struct PersistenceController {
+    static let shared = PersistenceController()
+
+    let container: NSPersistentCloudKitContainer
+
+    // CloudKit container identifier
+    static let cloudKitContainerIdentifier = "iCloud.dev.rzen.indie.Workouts"
+
+    var viewContext: NSManagedObjectContext {
+        container.viewContext
+    }
+
+    // MARK: - Preview Support
+
+    static var preview: PersistenceController = {
+        let controller = PersistenceController(inMemory: true)
+        let viewContext = controller.container.viewContext
+
+        // Create sample data for previews
+        let split = Split(context: viewContext)
+        split.name = "Upper Body"
+        split.color = "blue"
+        split.systemImage = "dumbbell.fill"
+        split.order = 0
+
+        let exercise = Exercise(context: viewContext)
+        exercise.name = "Bench Press"
+        exercise.sets = 3
+        exercise.reps = 10
+        exercise.weight = 135
+        exercise.order = 0
+        exercise.loadType = Int32(LoadType.weight.rawValue)
+        exercise.split = split
+
+        do {
+            try viewContext.save()
+        } catch {
+            let nsError = error as NSError
+            fatalError("Unresolved error \(nsError), \(nsError.userInfo)")
+        }
+
+        return controller
+    }()
+
+    // MARK: - Initialization
+
+    init(inMemory: Bool = false, cloudKitEnabled: Bool = true) {
+        container = NSPersistentCloudKitContainer(name: "Workouts")
+
+        guard let description = container.persistentStoreDescriptions.first else {
+            fatalError("Failed to retrieve a persistent store description.")
+        }
+
+        if inMemory {
+            description.url = URL(fileURLWithPath: "/dev/null")
+            description.cloudKitContainerOptions = nil
+        } else if cloudKitEnabled {
+            // Check if CloudKit is available before enabling
+            let cloudKitAvailable = FileManager.default.ubiquityIdentityToken != nil
+
+            if cloudKitAvailable {
+                // Set CloudKit container options
+                let cloudKitOptions = NSPersistentCloudKitContainerOptions(
+                    containerIdentifier: Self.cloudKitContainerIdentifier
+                )
+                description.cloudKitContainerOptions = cloudKitOptions
+            } else {
+                // CloudKit not available (not signed in, etc.)
+                description.cloudKitContainerOptions = nil
+                print("CloudKit not available - using local storage only")
+            }
+
+            // Enable persistent history tracking (useful even without CloudKit)
+            description.setOption(true as NSNumber, forKey: NSPersistentHistoryTrackingKey)
+            description.setOption(true as NSNumber, forKey: NSPersistentStoreRemoteChangeNotificationPostOptionKey)
+        } else {
+            // CloudKit explicitly disabled
+            description.cloudKitContainerOptions = nil
+        }
+
+        container.loadPersistentStores { storeDescription, error in
+            if let error = error as NSError? {
+                // In production, handle this more gracefully
+                print("CoreData error: \(error), \(error.userInfo)")
+                #if DEBUG
+                fatalError("Unresolved error \(error), \(error.userInfo)")
+                #endif
+            }
+        }
+
+        // Configure view context
+        container.viewContext.automaticallyMergesChangesFromParent = true
+        container.viewContext.mergePolicy = NSMergeByPropertyObjectTrumpMergePolicy
+
+        // Pin the viewContext to the current generation token
+        do {
+            try container.viewContext.setQueryGenerationFrom(.current)
+        } catch {
+            print("Failed to pin viewContext to the current generation: \(error)")
+        }
+    }
+
+    // MARK: - Save Context
+
+    func save() {
+        let context = container.viewContext
+        if context.hasChanges {
+            do {
+                try context.save()
+            } catch {
+                let nsError = error as NSError
+                print("Save error: \(nsError), \(nsError.userInfo)")
+            }
+        }
+    }
+}