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/Services/ICloudSyncService.swift

@@ -59,6 +59,7 @@ final class ICloudSyncService {
             settings: settings.map {
                 SettingsPayload(
                     mealWindows: $0.mealWindows,
+                    enabledMealTypesRaw: $0.enabledMealTypesRaw,
                     includeWeekends: $0.includeWeekends,
                     language: $0.language,
                     calendarId: $0.calendarId,
@@ -141,6 +142,7 @@ final class ICloudSyncService {
         if let settingsPayload = snapshot.settings {
             let settings = AppSettings()
             settings.mealWindows = settingsPayload.mealWindows
+            settings.enabledMealTypesRaw = settingsPayload.enabledMealTypesRaw
             settings.includeWeekends = settingsPayload.includeWeekends
             settings.language = settingsPayload.language
             settings.calendarId = settingsPayload.calendarId
@@ -227,6 +229,8 @@ private struct SyncSnapshot: Codable {
 
 private struct SettingsPayload: Codable {
     let mealWindows: String
+    // Optional for backward-compatibility with pre-2.0 snapshots.
+    let enabledMealTypesRaw: String?
     let includeWeekends: Bool
     let language: String
     let calendarId: String?