2.0: breakfast and snack meal types across the app

- MealType gains breakfast/snack (chronological order drives slot/row order).
- AppSettings.activeMealTypes: single source of truth for enabled meals, backed
  by new optional enabledMealTypesRaw with legacy mealWindows fallback —
  additive migration, keeps pre-2.0 installs and iCloud snapshots working.
  Legacy field kept coherent by the setter. time(for:) resolves per-meal event
  times (breakfast 8:00 / snack 17:00 defaults on old stores).
- Replaced the 5 duplicated mealWindows→[MealType] derivations (slot sync,
  default plan creation, week calendar, export view) with activeMealTypes.
- CalendarService: per-type event names and times.
- Export styles: per-type accent colors and gradients.
- Widget: generic meals list (N rows) instead of hardcoded lunch/dinner;
  compact families fall back to main meals when >2 are active.
- Settings: 4 meal toggles (min 1) replace the 3-option picker.
- Onboarding: meal step is now multi-select over the 4 types.
- iCloud sync: enabledMealTypesRaw synced (optional, pre-2.0 compatible).
- Localized breakfast/snack in all 6 languages.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BkanrydYtrme8wipTzWssG

MealMood/Views/Settings/SettingsView.swift

@@ -61,13 +61,26 @@ struct SettingsView: View {
         List {
             // Planning section
             Section {
-                Picker("settings_meal_windows", selection: Binding(
-                    get: { settings.mealWindowsEnum },
-                    set: { settings.mealWindowsEnum = $0 }
-                )) {
-                    Text("meal_windows_dinner_only").tag(MealWindows.dinnerOnly)
-                    Text("meal_windows_lunch_only").tag(MealWindows.lunchOnly)
-                    Text("meal_windows_both").tag(MealWindows.both)
+                ForEach(MealType.allCases, id: \.self) { mealType in
+                    Toggle(isOn: Binding(
+                        get: { settings.activeMealTypes.contains(mealType) },
+                        set: { enabled in
+                            var types = settings.activeMealTypes
+                            if enabled {
+                                types.append(mealType)
+                            } else if types.count > 1 {
+                                // Keep at least one meal type active.
+                                types.removeAll { $0 == mealType }
+                            }
+                            settings.activeMealTypes = types
+                        }
+                    )) {
+                        Label(
+                            String(localized: String.LocalizationValue(mealType.localizedKey)),
+                            systemImage: mealType.icon
+                        )
+                    }
+                    .tint(.mealMoodCoral)
                 }
 
                 Toggle("settings_include_weekends", isOn: Binding(