refactor(types): 重构类型系统，统一共享类型定义

feat(types): 新增共享类型中心，包含用户、产品、订单等核心领域类型
fix(types): 修复类型定义错误，统一各模块类型引用
style(types): 优化类型文件格式和注释
docs(types): 更新类型文档和变更日志
test(types): 添加类型测试用例
build(types): 配置类型共享路径
chore(types): 清理重复类型定义文件

dashboard/src/services/afterSalesDataSource.ts

@@ -7,7 +7,7 @@
  * @created 2026-03-19
  */
 
-import { IDataSource, IMockDataSource } from '@/types/datasource';
+import { IDataSource } from '@/types/datasource';
 
 // ============================================
 // 类型定义
@@ -108,7 +108,7 @@ class ApiAfterSalesDataSource implements IAfterSalesDataSource {
  * AI注意: 这是Mock实现，不是真实业务逻辑
  * 仅在REACT_APP_USE_MOCK=true时启用
  */
-class MockAfterSalesDataSource implements IAfterSalesDataSource, IMockDataSource {
+class MockAfterSalesDataSource implements IAfterSalesDataSource {
   readonly __MOCK__ = true as const;
   readonly __MOCK_NAME__ = 'MockAfterSalesDataSource';
 
@@ -193,6 +193,28 @@ class MockAfterSalesDataSource implements IAfterSalesDataSource, IMockDataSource
   private simulateDelay(ms: number): Promise<void> {
     return new Promise(resolve => setTimeout(resolve, ms));
   }
+
+  // Mock特定方法
+  reset(): void {
+    this.mockReturns = [
+      {
+        id: 'RET-001',
+        orderId: 'order-001',
+        returnReason: 'DEFECTIVE',
+        returnDescription: 'Product arrived damaged',
+        returnItems: ['item_001'],
+        images: [],
+        contactPhone: '+1 555-0123',
+        status: 'PENDING',
+        createdAt: '2026-03-18T10:00:00Z',
+        updatedAt: '2026-03-18T10:00:00Z',
+      },
+    ];
+  }
+
+  getMockData(): ReturnApplication[] {
+    return this.mockReturns;
+  }
 }
 
 // ============================================