feat: implement admin product management panel with bulk categorization and premium user toggle

flutter/lib/features/admin/data/admin_repository.dart

@@ -3,6 +3,8 @@ import '../../../core/api/api_client.dart';
 import '../../../core/api/api_paths.dart';
 import '../../../core/api/guarded_api_call.dart';
 import '../../auth/data/auth_providers.dart';
+import '../domain/admin_category_node.dart';
+import '../domain/admin_product.dart';
 import '../domain/ai_model_info.dart';
 import '../domain/pending_product.dart';
 import '../domain/user_admin.dart';
@@ -115,4 +117,36 @@ class AdminRepository {
         .map((e) => AiModelInfo.fromJson(e as Map<String, dynamic>))
         .toList();
   }
+
+  Future<List<AdminProduct>> listProducts() async {
+    final data = await guardedApiCall(
+      _ref,
+      () => _apiClient.getJson(ProductApiPaths.list),
+    );
+    return (data as List<dynamic>)
+        .map((e) => AdminProduct.fromJson(e as Map<String, dynamic>))
+        .toList();
+  }
+
+  Future<List<AdminCategoryNode>> listCategoryTree() async {
+    final data = await guardedApiCall(
+      _ref,
+      () => _apiClient.getJson(CategoryApiPaths.tree),
+    );
+    return (data as List<dynamic>)
+        .map((e) => AdminCategoryNode.fromJson(e as Map<String, dynamic>))
+        .toList();
+  }
+
+  Future<void> bulkSetCategory(List<int> ids, {required int? categoryId}) async {
+    final token = await _token();
+    await guardedApiCall(
+      _ref,
+      () => _apiClient.postJson(
+        ProductApiPaths.bulkUpdate,
+        body: {'ids': ids, 'categoryId': categoryId},
+        token: token,
+      ),
+    );
+  }
 }