Hotfix: accessors nil-tolerantes en Core Data — crashes de bridging con iCloud sync (build 56)

Dos crashes de producción con la misma causa raíz: atributos declarados
no-opcionales en Swift (@NSManaged id: UUID, date: Date) que llegan nil en
runtime — NSPersistentCloudKitContainer materializa registros de otros
dispositivos por fases y los objetos borrados pueden seguir referenciados por
vistas vivas. El force-bridge de nil revienta:

1. UUID._unconditionallyBridgeFromObjectiveC en ForEach (keypath Identifiable.id)
2. Date._unconditionallyBridgeFromObjectiveC en ChartsViewModel.monthlyTotals

Fix sistémico (no por call-site): NSManagedObject.safeValue(forKey:fallback:healing:)
lee el primitive y cae a un valor seguro; id se auto-cura (UUID nuevo escrito al
primitive sin ensuciar el objeto). Aplicado a:
- Snapshot: id (heal), date, createdAt (fallback distantPast)
- InvestmentSource / Goal / Account: id (heal), name (fallback "")
- Category: id (heal), name, colorHex, icon (fallbacks neutros)

Los accessors son @objc → NSSortDescriptor(keyPath:) y KVC siguen funcionando.
awakeFromInsert/awakeFromFetch se mantienen. Smoke test UITest en verde.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WoScpmHdVj1aUf4rAp6hbe

PortfolioJournal/Models/CoreData/Account+CoreDataClass.swift

@@ -7,8 +7,14 @@ public class Account: NSManagedObject, Identifiable {
         return NSFetchRequest<Account>(entityName: "Account")
     }
 
-    @NSManaged public var id: UUID
-    @NSManaged public var name: String
+    @objc public var id: UUID {
+        get { safeValue(forKey: "id", fallback: UUID(), healing: true) }
+        set { setManagedValue(newValue, forKey: "id") }
+    }
+    @objc public var name: String {
+        get { safeValue(forKey: "name", fallback: "") }
+        set { setManagedValue(newValue, forKey: "name") }
+    }
     @NSManaged public var createdAt: Date
     @NSManaged public var currency: String?
     @NSManaged public var inputMode: String

PortfolioJournal/Models/CoreData/Category+CoreDataClass.swift

@@ -8,10 +8,22 @@ public class Category: NSManagedObject, Identifiable {
         return NSFetchRequest<Category>(entityName: "Category")
     }
 
-    @NSManaged public var id: UUID
-    @NSManaged public var name: String
-    @NSManaged public var colorHex: String
-    @NSManaged public var icon: String
+    @objc public var id: UUID {
+        get { safeValue(forKey: "id", fallback: UUID(), healing: true) }
+        set { setManagedValue(newValue, forKey: "id") }
+    }
+    @objc public var name: String {
+        get { safeValue(forKey: "name", fallback: "") }
+        set { setManagedValue(newValue, forKey: "name") }
+    }
+    @objc public var colorHex: String {
+        get { safeValue(forKey: "colorHex", fallback: "#6B7280") }
+        set { setManagedValue(newValue, forKey: "colorHex") }
+    }
+    @objc public var icon: String {
+        get { safeValue(forKey: "icon", fallback: "questionmark") }
+        set { setManagedValue(newValue, forKey: "icon") }
+    }
     @NSManaged public var sortOrder: Int16
     @NSManaged public var createdAt: Date
     @NSManaged public var allocationTarget: NSNumber?

PortfolioJournal/Models/CoreData/Goal+CoreDataClass.swift

@@ -7,8 +7,14 @@ public class Goal: NSManagedObject, Identifiable {
         return NSFetchRequest<Goal>(entityName: "Goal")
     }
 
-    @NSManaged public var id: UUID
-    @NSManaged public var name: String
+    @objc public var id: UUID {
+        get { safeValue(forKey: "id", fallback: UUID(), healing: true) }
+        set { setManagedValue(newValue, forKey: "id") }
+    }
+    @objc public var name: String {
+        get { safeValue(forKey: "name", fallback: "") }
+        set { setManagedValue(newValue, forKey: "name") }
+    }
     @NSManaged public var targetAmount: NSDecimalNumber?
     @NSManaged public var targetDate: Date?
     @NSManaged public var isActive: Bool

PortfolioJournal/Models/CoreData/InvestmentSource+CoreDataClass.swift

@@ -7,8 +7,14 @@ public class InvestmentSource: NSManagedObject, Identifiable {
         return NSFetchRequest<InvestmentSource>(entityName: "InvestmentSource")
     }
 
-    @NSManaged public var id: UUID
-    @NSManaged public var name: String
+    @objc public var id: UUID {
+        get { safeValue(forKey: "id", fallback: UUID(), healing: true) }
+        set { setManagedValue(newValue, forKey: "id") }
+    }
+    @objc public var name: String {
+        get { safeValue(forKey: "name", fallback: "") }
+        set { setManagedValue(newValue, forKey: "name") }
+    }
     @NSManaged public var notificationFrequency: String
     @NSManaged public var customFrequencyMonths: Int16
     @NSManaged public var isActive: Bool

PortfolioJournal/Models/CoreData/NSManagedObject+SafeAccessors.swift

@@ -0,0 +1,34 @@
+import CoreData
+
+// MARK: - Nil-tolerant accessors for CloudKit-synced attributes
+//
+// Attributes declared non-optional in Swift (`id: UUID`, `date: Date`, …) CAN
+// be nil at runtime: NSPersistentCloudKitContainer merges records from other
+// devices in stages, and deleted objects may still be referenced by live views.
+// Reading them through `@NSManaged` force-bridges nil and crashes
+// (`UUID/Date._unconditionallyBridgeFromObjectiveC`) — seen in production in
+// SwiftUI ForEach identity (nil id) and ChartsViewModel.monthlyTotals (nil
+// date). These helpers read the primitive value and fall back safely.
+extension NSManagedObject {
+    /// Reads a primitive attribute, returning `fallback` when nil. With
+    /// `healing: true` the fallback is also written back to the primitive
+    /// (without dirtying the object) so identity stays stable for the session.
+    func safeValue<T>(forKey key: String, fallback: @autoclosure () -> T, healing: Bool = false) -> T {
+        willAccessValue(forKey: key)
+        defer { didAccessValue(forKey: key) }
+        if let value = primitiveValue(forKey: key) as? T {
+            return value
+        }
+        let healed = fallback()
+        if healing {
+            setPrimitiveValue(healed, forKey: key)
+        }
+        return healed
+    }
+
+    func setManagedValue<T>(_ value: T, forKey key: String) {
+        willChangeValue(forKey: key)
+        setPrimitiveValue(value, forKey: key)
+        didChangeValue(forKey: key)
+    }
+}

PortfolioJournal/Models/CoreData/Snapshot+CoreDataClass.swift

@@ -7,12 +7,21 @@ public class Snapshot: NSManagedObject, Identifiable {
         return NSFetchRequest<Snapshot>(entityName: "Snapshot")
     }
 
-    @NSManaged public var id: UUID
-    @NSManaged public var date: Date
+    @objc public var id: UUID {
+        get { safeValue(forKey: "id", fallback: UUID(), healing: true) }
+        set { setManagedValue(newValue, forKey: "id") }
+    }
+    @objc public var date: Date {
+        get { safeValue(forKey: "date", fallback: .distantPast) }
+        set { setManagedValue(newValue, forKey: "date") }
+    }
     @NSManaged public var value: NSDecimalNumber?
     @NSManaged public var contribution: NSDecimalNumber?
     @NSManaged public var notes: String?
-    @NSManaged public var createdAt: Date
+    @objc public var createdAt: Date {
+        get { safeValue(forKey: "createdAt", fallback: .distantPast) }
+        set { setManagedValue(newValue, forKey: "createdAt") }
+    }
     @NSManaged public var source: InvestmentSource?
 
     public override func awakeFromInsert() {