Autocomplete feedback loop: implicit rejection + weekly rating

A) Implicit: HomeViewModel tracks auto-assigned slot IDs after each
   autocomplete run. When the user manually replaces one of those dishes,
   the rejected dish ID is recorded in FeedbackStore (UserDefaults).
   AutocompleteEngine applies a 25% penalty per rejection (floor 0.30).

B) Explicit: WeekPlan gains userRating (0/1/-1). Past weeks with dishes
   show a compact 👍/👎 row (Premium only). Liked weeks boost their
   dishes (+0.20 each, max +0.50); disliked weeks penalise them
   (-0.25 each, max -0.50). Signal is intentionally modest so the
   period cycle score remains dominant.

Also adds Stats + week-rating localization strings to all 6 languages
(were missing from the previous commit).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

MealMood/Models/WeekPlan.swift

@@ -7,6 +7,7 @@ final class WeekPlan {
     var weekStartDate: Date
     var createdAt: Date
     var updatedAt: Date
+    var userRating: Int = 0   // 0 = unrated, 1 = liked, -1 = disliked
 
     @Relationship(deleteRule: .cascade)
     var slots: [MealSlot]
@@ -23,5 +24,6 @@ final class WeekPlan {
         self.slots = slots
         self.createdAt = createdAt
         self.updatedAt = updatedAt
+        self.userRating = 0
     }
 }