feat: 删除JSP视图层，完善评价和通知系统，新增拼团模块

- 删除所有 JSP 页面（20个文件），前端完全迁移至 Vue 3 SPA
- 完善评价系统：ReviewDialog 组件、用户评价历史页、评价状态检查API
- 新增通知系统：Notification 实体/仓库/服务/控制器，NotificationCenter 接入真实API
- 新增拼团模块：GroupBuying 全套后端和前端页面
- 修复 review check API 参数双重包装导致请求格式错误
- 修复通知 API 路径缺少 /api 前缀和响应格式处理
- MessageListenerService 集成 NotificationService 创建持久化通知

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

flash-sale-frontend/package.json

@@ -8,7 +8,10 @@
     "build": "vue-tsc && vite build",
     "preview": "vite preview",
     "lint": "eslint . --ext .vue,.js,.jsx,.cjs,.mjs,.ts,.tsx,.cts,.mts --fix --ignore-path .gitignore",
-    "format": "prettier --write src/"
+    "format": "prettier --write src/",
+    "test:e2e": "playwright test",
+    "test:e2e:headed": "playwright test --headed",
+    "test:e2e:ui": "playwright test --ui"
   },
   "dependencies": {
     "vue": "^3.4.15",
@@ -43,6 +46,7 @@
     "@typescript-eslint/parser": "^6.19.0",
     "prettier": "^3.2.4",
     "@vue/eslint-config-prettier": "^9.0.0",
-    "@vue/eslint-config-typescript": "^12.0.0"
+    "@vue/eslint-config-typescript": "^12.0.0",
+    "@playwright/test": "^1.52.0"
   }
-}
+}