feat(ios): add Core Data DAO layer and unit tests

Implement comprehensive data access layer for Core Data entities:

- Add NotificationContentDAO, NotificationDeliveryDAO, and NotificationConfigDAO
  with full CRUD operations and query helpers
- Add DailyNotificationDataConversions utility for type conversions
  (Date ↔ Int64, Int ↔ Int32, JSON, optional strings)
- Update PersistenceController with entity verification and migration policies
- Add comprehensive unit tests for all DAO classes and data conversions
- Update Core Data model with NotificationContent, NotificationDelivery,
  and NotificationConfig entities (relationships and indexes)
- Integrate ReactivationManager into DailyNotificationPlugin.load()

DAO Features:
- Create/Insert methods with dictionary support
- Read/Query methods with predicates (by timesafariDid, notificationType,
  scheduledTime range, deliveryStatus, etc.)
- Update methods (touch, updateDeliveryStatus, recordUserInteraction)
- Delete methods (by ID, by key, delete all)
- Relationship management (NotificationContent ↔ NotificationDelivery)
- Cascade delete support

Test Coverage:
- 328 lines: DailyNotificationDataConversionsTests (time, numeric, string, JSON)
- 490 lines: NotificationContentDAOTests (CRUD, queries, updates)
- 415 lines: NotificationDeliveryDAOTests (CRUD, relationships, cascade delete)
- 412 lines: NotificationConfigDAOTests (CRUD, queries, active filtering)

All tests use in-memory Core Data stack for isolation and speed.

Completes sections 4.4, 4.5, and 6.0 of iOS implementation checklist.

ios/Plugin/DailyNotificationModel.swift

@@ -116,9 +116,10 @@ extension History: Identifiable {
 
 // MARK: - Persistence Controller
 // Phase 2: CoreData integration for advanced features
-// Phase 1: Stubbed out - CoreData model not yet created
+// All entities now available: ContentCache, Schedule, Callback, History,
+// NotificationContent, NotificationDelivery, NotificationConfig
 class PersistenceController {
-    // Lazy initialization to prevent Phase 1 errors
+    // Lazy initialization
     private static var _shared: PersistenceController?
     static var shared: PersistenceController {
         if _shared == nil {
@@ -131,8 +132,6 @@ class PersistenceController {
     private var initializationError: Error?
     
     init(inMemory: Bool = false) {
-        // Phase 1: CoreData model doesn't exist yet, so we'll handle gracefully
-        // Phase 2: Will create DailyNotificationModel.xcdatamodeld
         var tempContainer: NSPersistentContainer? = nil
         
         do {
@@ -142,12 +141,23 @@ class PersistenceController {
                 tempContainer?.persistentStoreDescriptions.first?.url = URL(fileURLWithPath: "/dev/null")
             }
             
+            // Configure persistent store options
+            let description = tempContainer?.persistentStoreDescriptions.first
+            description?.shouldMigrateStoreAutomatically = true
+            description?.shouldInferMappingModelAutomatically = true
+            
             var loadError: Error? = nil
-            tempContainer?.loadPersistentStores { _, error in
+            tempContainer?.loadPersistentStores { description, error in
                 if let error = error as NSError? {
                     loadError = error
-                    print("DNP-PLUGIN: CoreData model not found (Phase 1 - expected). Error: \(error.localizedDescription)")
-                    print("DNP-PLUGIN: CoreData features will be available in Phase 2")
+                    print("DNP-PLUGIN: CoreData store load error: \(error.localizedDescription)")
+                    print("DNP-PLUGIN: Error domain: \(error.domain), code: \(error.code)")
+                    if let failureReason = error.userInfo[NSLocalizedFailureReasonErrorKey] as? String {
+                        print("DNP-PLUGIN: Failure reason: \(failureReason)")
+                    }
+                } else {
+                    print("DNP-PLUGIN: CoreData store loaded successfully")
+                    print("DNP-PLUGIN: Store URL: \(description.url?.absoluteString ?? "unknown")")
                 }
             }
             
@@ -155,7 +165,14 @@ class PersistenceController {
                 self.initializationError = error
                 self.container = nil
             } else {
-                tempContainer?.viewContext.automaticallyMergesChangesFromParent = true
+                // Configure view context
+                if let context = tempContainer?.viewContext {
+                    context.automaticallyMergesChangesFromParent = true
+                    context.mergePolicy = NSMergeByPropertyObjectTrumpMergePolicy
+                    
+                    // Verify all entities are available
+                    verifyEntities(in: context)
+                }
                 self.container = tempContainer
             }
         } catch {
@@ -166,10 +183,88 @@ class PersistenceController {
     }
     
     /**
-     * Check if CoreData is available (Phase 2+)
+     * Check if CoreData is available
      */
     var isAvailable: Bool {
         return container != nil && initializationError == nil
     }
+    
+    /**
+     * Get the main view context
+     * 
+     * @return NSManagedObjectContext or nil if not available
+     */
+    var viewContext: NSManagedObjectContext? {
+        return container?.viewContext
+    }
+    
+    /**
+     * Create a new background context for async operations
+     * 
+     * @return NSManagedObjectContext or nil if not available
+     */
+    func newBackgroundContext() -> NSManagedObjectContext? {
+        return container?.newBackgroundContext()
+    }
+    
+    /**
+     * Save the view context
+     * 
+     * @return true if saved successfully, false otherwise
+     */
+    func save() -> Bool {
+        guard let context = viewContext else {
+            print("DNP-PLUGIN: Cannot save - CoreData not available")
+            return false
+        }
+        
+        if context.hasChanges {
+            do {
+                try context.save()
+                print("DNP-PLUGIN: CoreData context saved successfully")
+                return true
+            } catch {
+                print("DNP-PLUGIN: Error saving CoreData context: \(error.localizedDescription)")
+                context.rollback()
+                return false
+            }
+        }
+        return true
+    }
+    
+    /**
+     * Verify all entities are available in the model
+     * 
+     * @param context Managed object context
+     */
+    private func verifyEntities(in context: NSManagedObjectContext) {
+        guard let model = context.persistentStoreCoordinator?.managedObjectModel else {
+            print("DNP-PLUGIN: Cannot verify entities - no managed object model")
+            return
+        }
+        
+        let entityNames = [
+            "ContentCache",
+            "Schedule",
+            "Callback",
+            "History",
+            "NotificationContent",
+            "NotificationDelivery",
+            "NotificationConfig"
+        ]
+        
+        var missingEntities: [String] = []
+        for entityName in entityNames {
+            if model.entitiesByName[entityName] == nil {
+                missingEntities.append(entityName)
+            }
+        }
+        
+        if missingEntities.isEmpty {
+            print("DNP-PLUGIN: All \(entityNames.count) entities verified in CoreData model")
+        } else {
+            print("DNP-PLUGIN: WARNING - Missing entities: \(missingEntities.joined(separator: ", "))")
+        }
+    }
 }