Fix Reset All Data crash by using safe cascade deletion

MealMood/Services/DefaultDataService.swift

@@ -3,7 +3,7 @@ import SwiftData
 
 struct DefaultDataService {
 
-    static func createDefaultTags(context: ModelContext) {
+    static func createDefaultTags(context: ModelContext, saveImmediately: Bool = true) {
         let defaults: [(name: String, nameEN: String, color: String, maxPerWeek: Int?, noConsecutive: Bool, noDuplicateInDay: Bool, mealTypeRestriction: String?, sortOrder: Int)] = [
             ("Carne", "Meat", "#E74C3C", 3, true, true, nil, 0),
             ("Pescado", "Fish", "#3498DB", 2, true, true, nil, 1),
@@ -32,7 +32,9 @@ struct DefaultDataService {
             context.insert(tag)
         }
 
-        try? context.save()
+        if saveImmediately {
+            try? context.save()
+        }
     }
 
     static func createDefaultSettings(context: ModelContext) {

MealMood/ViewModels/SettingsViewModel.swift

@@ -68,11 +68,11 @@ final class SettingsViewModel: ObservableObject {
 
     func resetAllData(context: ModelContext) {
         do {
-            try deleteAll(of: MealSlot.self, in: context)
+            // WeekPlan cascades MealSlot, so deleting both can corrupt the reset flow.
             try deleteAll(of: WeekPlan.self, in: context)
             try deleteAll(of: Dish.self, in: context)
             try deleteAll(of: Tag.self, in: context)
-            DefaultDataService.createDefaultTags(context: context)
+            DefaultDataService.createDefaultTags(context: context, saveImmediately: false)
 
             let settingsDescriptor = FetchDescriptor<AppSettings>()
             if let existingSettings = try context.fetch(settingsDescriptor).first {
@@ -98,7 +98,6 @@ final class SettingsViewModel: ObservableObject {
         for model in models {
             context.delete(model)
         }
-        try context.save()
     }
 
     private func showToastMessage(_ message: String) {