fix: show dish calories in search and fix portion sheet layout crash

- DishSearchResult now carries calories_per_serving (backend entity + repo
  LEFT JOIN recipes / MIN / GROUP BY; Flutter model + fromJson)
- _FoodTile.fromDish shows kcal/serving subtitle when available
- _DishPortionSheet quick-select buttons: Row → Wrap to avoid
  BoxConstraints infinite-width crash inside DraggableScrollableSheet

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

client/lib/features/diary/food_search_service.dart

@@ -7,12 +7,14 @@ class DishSearchResult {
   final String name;
   final String? imageUrl;
   final double avgRating;
+  final double? caloriesPerServing;
 
   const DishSearchResult({
     required this.id,
     required this.name,
     this.imageUrl,
     required this.avgRating,
+    this.caloriesPerServing,
   });
 
   factory DishSearchResult.fromJson(Map<String, dynamic> json) {
@@ -21,6 +23,8 @@ class DishSearchResult {
       name: json['name'] as String,
       imageUrl: json['image_url'] as String?,
       avgRating: (json['avg_rating'] as num?)?.toDouble() ?? 0,
+      caloriesPerServing:
+          (json['calories_per_serving'] as num?)?.toDouble(),
     );
   }
 }