reglas: plato fijo por dia y comida (ej. tortilla los viernes de cena)

- Dish.fixedDayOfWeek/fixedMealType (opcionales, aditivos para CloudKit)
- Toggle + pickers de dia/comida en el formulario de plato
- AutocompleteEngine: pre-pasada que asigna los platos fijos a su hueco
  antes del bucle MRV, de modo que cuentan para el resto de reglas
- Evento analytics dish_fixed_slot_set; strings en 6 idiomas

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013H6bXqGX1ygwib1Dm3n3UG

MealMood/Models/Dish.swift

@@ -20,6 +20,12 @@ final class Dish {
     /// CloudKit-friendly.
     @Attribute(.externalStorage) var photoData: Data?
 
+    /// Fixed-slot rule ("tortilla every Friday dinner"): when both are set,
+    /// autocomplete pins this dish to that weekday+meal before filling the
+    /// rest of the week. 0=Monday … 6=Sunday, matching `MealSlot.dayOfWeek`.
+    var fixedDayOfWeek: Int?
+    var fixedMealType: String?
+
     init(
         id: UUID = UUID(),
         name: String,
@@ -28,7 +34,9 @@ final class Dish {
         createdAt: Date = Date(),
         isPriority: Bool = false,
         ingredients: [String] = [],
-        photoData: Data? = nil
+        photoData: Data? = nil,
+        fixedDayOfWeek: Int? = nil,
+        fixedMealType: String? = nil
     ) {
         self.id = id
         self.name = name
@@ -38,6 +46,8 @@ final class Dish {
         self.isPriority = isPriority
         self.ingredients = ingredients
         self.photoData = photoData
+        self.fixedDayOfWeek = fixedDayOfWeek
+        self.fixedMealType = fixedMealType
     }
 }