2.0: Dish gains optional ingredients + photo; on-device ingredient generation

- Dish: ingredients [String] (default [], never required) and photoData
  (externalStorage). Additive SwiftData migration — existing stores unaffected.
- ICloudSyncService: sync ingredients (optional in payload so pre-2.0 snapshots
  still decode); photos deliberately excluded from KV sync (1MB limit).
- IngredientGenerator: Foundation Models (iOS 26+) generates localized
  ingredient lines from the dish name, fully on-device. isAvailable gates the
  UI affordance on older OS/devices; failures record to Crashlytics and
  return [].

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

MealMood/Models/Dish.swift

@@ -10,13 +10,24 @@ final class Dish {
     var createdAt: Date
     var isPriority: Bool = false
 
+    /// Optional ingredient lines (one per entry, e.g. "200g spaghetti").
+    /// Populated lazily — manually or via on-device generation — and only for
+    /// the dishes a user actually shops for. Never required to create a dish.
+    var ingredients: [String] = []
+
+    /// Optional dish photo. Stored outside the main store to keep it light and
+    /// CloudKit-friendly.
+    @Attribute(.externalStorage) var photoData: Data?
+
     init(
         id: UUID = UUID(),
         name: String,
         descriptionText: String? = nil,
         tagIds: [UUID] = [],
         createdAt: Date = Date(),
-        isPriority: Bool = false
+        isPriority: Bool = false,
+        ingredients: [String] = [],
+        photoData: Data? = nil
     ) {
         self.id = id
         self.name = name
@@ -24,6 +35,8 @@ final class Dish {
         self.tagIds = tagIds
         self.createdAt = createdAt
         self.isPriority = isPriority
+        self.ingredients = ingredients
+        self.photoData = photoData
     }
 }