Base fixes and test harness

PortfolioJournal/Models/CoreData/InvestmentSource+CoreDataClass.swift

@@ -28,6 +28,14 @@ public class InvestmentSource: NSManagedObject, Identifiable {
         customFrequencyMonths = 1
         name = ""
     }
+
+    public override func awakeFromFetch() {
+        super.awakeFromFetch()
+        // Defensive: ensure id exists for legacy rows where id may be nil.
+        if value(forKey: "id") == nil {
+            setValue(UUID(), forKey: "id")
+        }
+    }
 }
 
 // MARK: - Notification Frequency

PortfolioJournal/Models/CoreData/Snapshot+CoreDataClass.swift

@@ -21,11 +21,35 @@ public class Snapshot: NSManagedObject, Identifiable {
         date = Date()
         createdAt = Date()
     }
+
+    public override func awakeFromFetch() {
+        super.awakeFromFetch()
+        // Defensive: ensure id exists for legacy rows where id may be nil.
+        if value(forKey: "id") == nil {
+            setValue(UUID(), forKey: "id")
+        }
+    }
 }
 
 // MARK: - Computed Properties
 
 extension Snapshot {
+    var safeId: UUID {
+        if let existing = primitiveValue(forKey: "id") as? UUID {
+            return existing
+        }
+        let newId = UUID()
+        setPrimitiveValue(newId, forKey: "id")
+        return newId
+    }
+
+    var safeDate: Date {
+        if let dateValue = primitiveValue(forKey: "date") as? Date {
+            return dateValue
+        }
+        return Date()
+    }
+
     var decimalValue: Decimal {
         value?.decimalValue ?? Decimal.zero
     }