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/admin/domain/user_admin.dart

@@ -7,6 +7,7 @@ class UserAdmin {
   final String? lastName;
   final String role;
   final bool isPremium;
+  final bool canShareRecipes;
   final DateTime? createdAt;
 
   const UserAdmin({
@@ -17,6 +18,7 @@ class UserAdmin {
     this.lastName,
     required this.role,
     required this.isPremium,
+    required this.canShareRecipes,
     this.createdAt,
   });
 
@@ -28,6 +30,7 @@ class UserAdmin {
         lastName: json['lastName'] as String?,
         role: json['role'] as String? ?? 'user',
         isPremium: json['isPremium'] as bool? ?? false,
+        canShareRecipes: json['canShareRecipes'] as bool? ?? true,
         createdAt: json['createdAt'] != null ? DateTime.tryParse(json['createdAt'] as String) : null,
       );