tests: target MealMoodUITests que recorre el onboarding completo

El bug de los pasos 5 y 6 era invisible a los tests unitarios: el contrato de
datos estaba bien, lo que fallaba era que la vista se desmontaba antes de pintar
el aha moment y el paywall. Hace falta recorrer la UI de verdad.

Anade el target MealMoodUITests (solo simulador, sin firma) y un test que hace
el onboarding entero en instalacion limpia y comprueba que Week Ready y el
paywall aparecen antes de la Home.

Los CTA del onboarding llevan ahora accessibilityIdentifier para que el test no
dependa de los textos, que estan en 6 idiomas.

Validado en los dos sentidos: pasa con el fix, y revirtiendo temporalmente
markFinished: false falla en la asercion de Week Ready. Suite completa: 27 tests.

Co-Authored-By: Claude <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012Ks8uUcMA9mjypVK7F2Pkt

MealMood/Views/Home/HomeView.swift

@@ -115,6 +115,7 @@ struct HomeView: View {
                     }
                 }
             }
+            .accessibilityIdentifier("home_root")
             .toast(isShowing: $viewModel.showToast, message: viewModel.toastMessage)
             .navigationTitle("")
             .navigationBarTitleDisplayMode(.inline)

MealMood/Views/Onboarding/CalendarStepView.swift

@@ -137,6 +137,7 @@ struct CalendarStepView: View {
                     })
 
                     PrimaryButton(title: String(localized: "onboarding_continue"), action: onNext)
+                        .accessibilityIdentifier("onboarding_cta_calendar")
                 }
                 .padding(.horizontal, 24)
                 .padding(.bottom, 40)

MealMood/Views/Onboarding/FirstDishesStepView.swift

@@ -241,6 +241,7 @@ struct FirstDishesStepView: View {
                     },
                     isEnabled: true
                 )
+                .accessibilityIdentifier("onboarding_cta_first_dishes")
                 .padding(.horizontal, 24)
                 .padding(.top, 12)
                 .padding(.bottom, 24)

MealMood/Views/Onboarding/MealWindowsStepView.swift

@@ -38,6 +38,7 @@ struct MealWindowsStepView: View {
             .padding(.horizontal, 24)
 
             PrimaryButton(title: String(localized: "onboarding_continue"), action: onNext)
+                .accessibilityIdentifier("onboarding_cta_meal_windows")
                 .padding(.horizontal, 24)
                 .padding(.top, 8)
                 .padding(.bottom, 40)

MealMood/Views/Onboarding/PaywallStepView.swift

@@ -59,6 +59,7 @@ struct PaywallStepView: View {
                             .font(.mealMoodSmall)
                             .foregroundColor(.mealMoodTextSecondary)
                     }
+                    .accessibilityIdentifier("onboarding_cta_paywall_skip")
                 }
                 .padding(.horizontal, 24)
                 .padding(.bottom, 24)

MealMood/Views/Onboarding/WeekReadyStepView.swift

@@ -26,6 +26,7 @@ struct WeekReadyStepView: View {
                     .font(.mealMoodH1)
                     .foregroundColor(.mealMoodTextPrimary)
                     .multilineTextAlignment(.center)
+                    .accessibilityIdentifier("onboarding_week_ready_title")
 
                 Text(subtitleText)
                     .font(.mealMoodBody)
@@ -81,6 +82,7 @@ struct WeekReadyStepView: View {
                             .foregroundColor(.mealMoodTextSecondary)
                     }
                     .buttonStyle(.plain)
+                    .accessibilityIdentifier("onboarding_cta_week_ready_skip")
                 }
             }
             .padding(.horizontal, 24)

MealMood/Views/Onboarding/WeekendsStepView.swift

@@ -41,6 +41,7 @@ struct WeekendsStepView: View {
                 .foregroundColor(.mealMoodTextSecondary)
 
             PrimaryButton(title: String(localized: "onboarding_continue"), action: onNext)
+                .accessibilityIdentifier("onboarding_cta_weekends")
                 .padding(.horizontal, 24)
                 .padding(.top, 8)
                 .padding(.bottom, 40)

MealMood/Views/Onboarding/WelcomeStepView.swift

@@ -30,6 +30,7 @@ struct WelcomeStepView: View {
             Spacer()
 
             PrimaryButton(title: String(localized: "onboarding_start"), icon: "✨", action: onNext)
+                .accessibilityIdentifier("onboarding_cta_welcome")
                 .padding(.horizontal, 24)
                 .padding(.bottom, 40)
         }