feat(recipes): add recipe visibility and sharing features

- Implemented functionality to set recipe visibility (public/private) with appropriate checks for user permissions.
- Added ability to share recipes with other users, including validation for existing users and permissions.
- Introduced new DTOs for setting visibility and sharing recipes.
- Updated RecipesController and RecipesService to handle new endpoints for visibility and sharing.
- Enhanced inventory preview to consider user permissions and shared recipes.
- Updated front-end to support new sharing and visibility features, including UI changes for recipe detail and admin user management.

flutter/lib/features/recipes/domain/recipe.dart

@@ -8,6 +8,10 @@ class Recipe {
   final int? servings;
   final String? instructions;
   final List<RecipeIngredient> ingredients;
+  final bool isPublic;
+  final int? ownerId;
+  final String? ownerUsername;
+  final List<int> sharedWithUserIds;
 
   const Recipe({
     required this.id,
@@ -17,6 +21,10 @@ class Recipe {
     this.servings,
     this.instructions,
     this.ingredients = const [],
+    this.isPublic = false,
+    this.ownerId,
+    this.ownerUsername,
+    this.sharedWithUserIds = const [],
   });
 
   factory Recipe.fromJson(Map<String, dynamic> json) {
@@ -27,6 +35,8 @@ class Recipe {
     final dynamic rawServings = json['servings'];
     final rawIngredients = json['ingredients'] as List<dynamic>? ?? [];
     final normalizedImageUrl = rawImageUrl?.toString().trim();
+    final ownerJson = json['owner'] as Map<String, dynamic>?;
+    final sharesJson = json['shares'] as List<dynamic>? ?? const [];
 
     return Recipe(
       id: rawId is num ? rawId.toInt() : int.parse(rawId.toString()),
@@ -45,6 +55,18 @@ class Recipe {
       ingredients: rawIngredients
           .map((i) => RecipeIngredient.fromJson(i as Map<String, dynamic>))
           .toList(),
+        isPublic: json['isPublic'] == true,
+        ownerId: ownerJson == null
+          ? null
+          : (ownerJson['id'] is num
+            ? (ownerJson['id'] as num).toInt()
+            : int.tryParse('${ownerJson['id']}')),
+        ownerUsername: ownerJson?['username']?.toString(),
+        sharedWithUserIds: sharesJson
+          .map((s) => (s as Map<String, dynamic>)['userId'])
+          .whereType<num>()
+          .map((id) => id.toInt())
+          .toList(),
     );
   }
 }