feat(inventory): add inventory preview functionality and related models

flutter/lib/features/recipes/data/recipe_repository.dart

@@ -3,6 +3,7 @@ import '../../../core/api/api_exception.dart';
 import '../../../core/api/api_paths.dart';
 import '../domain/parsed_recipe.dart';
 import '../domain/recipe.dart';
+import '../domain/inventory_preview.dart';
 
 class RecipeRepository {
   final ApiClient _api;
@@ -93,6 +94,27 @@ class RecipeRepository {
     }
   }
 
+  Future<InventoryPreview> fetchInventoryPreview(int id,
+      {String? token}) async {
+    try {
+      final data = await _api.getJson(
+        RecipeApiPaths.inventoryPreview(id),
+        token: token,
+      );
+      if (data is! Map<String, dynamic>) {
+        throw const ApiException(
+            type: ApiErrorType.unknown, message: 'Ogiltigt svar från servern.');
+      }
+      return InventoryPreview.fromJson(data);
+    } on ApiException {
+      rethrow;
+    } catch (_) {
+      throw const ApiException(
+          type: ApiErrorType.network,
+          message: 'Kunde inte hämta inventariestatus.');
+    }
+  }
+
   Future<ParsedRecipe> parseMarkdown(String markdown,
       {String? token}) async {
     try {