feat(client): 商品基础数据加香型字典 tab（接后端 categories CRUD）

新增 ProductCategoryOption 模型 + repo（list/create/update/deleteCategory）+
provider（productCategoryListProvider），基础数据页加「香型」tab（增删改查、
搜索、导出，仅名称字段）。接通后端 /product-options/categories。
（原型 5-tab 整合是更大 IA 任务，本次先把香型管理补齐可用。）

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TSKEiHsvauyxYUW2itzUXX

client/lib/repositories/product_option_repository.dart

@@ -88,6 +88,48 @@ class ProductOptionRepository {
     }
   }
 
+  // ── 香型 / 分类 ──────────────────────────────────────────────
+
+  Future<List<ProductCategoryOption>> listCategories() async {
+    try {
+      final resp = await _client.get('/product-options/categories');
+      final data = (resp.data as Map<String, dynamic>)['data'] as List? ?? [];
+      return data
+          .map((e) => ProductCategoryOption.fromJson(e as Map<String, dynamic>))
+          .toList();
+    } on DioException catch (e) {
+      throw AppException(e.response?.data?['error'] as String? ?? '获取香型列表失败',
+          statusCode: e.response?.statusCode);
+    }
+  }
+
+  Future<void> createCategory(Map<String, dynamic> data) async {
+    try {
+      await _client.post('/product-options/categories', data: data);
+    } on DioException catch (e) {
+      throw AppException(e.response?.data?['error'] as String? ?? '创建失败',
+          statusCode: e.response?.statusCode);
+    }
+  }
+
+  Future<void> updateCategory(int id, Map<String, dynamic> data) async {
+    try {
+      await _client.put('/product-options/categories/$id', data: data);
+    } on DioException catch (e) {
+      throw AppException(e.response?.data?['error'] as String? ?? '更新失败',
+          statusCode: e.response?.statusCode);
+    }
+  }
+
+  Future<void> deleteCategory(int id) async {
+    try {
+      await _client.delete('/product-options/categories/$id');
+    } on DioException catch (e) {
+      throw AppException(e.response?.data?['error'] as String? ?? '删除失败',
+          statusCode: e.response?.statusCode);
+    }
+  }
+
   // ── 规格 ────────────────────────────────────────────────────
 
   Future<List<ProductSpecOption>> listSpecs() async {