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/src/utils/normalizers.ts

@@ -1,6 +1,8 @@
 import type {
   CartItem,
   FlashSale,
+  GroupBuying,
+  GroupBuyingGroup,
   Order,
   OrderAddress,
   PageResponse,
@@ -285,3 +287,69 @@ export const normalizeAdminProduct = (product: Record<string, any>): AdminProduc
   viewCount: toNumber(product.viewCount),
   rating: toNumber(product.rating),
 })
+
+export const mapGroupBuyingStatus = (status: number | string): GroupBuying['status'] => {
+  const value = typeof status === 'string' ? status : toNumber(status)
+  if (value === 'DRAFT' || value === 0) return 'DRAFT'
+  if (value === 'UPCOMING' || value === 1) return 'UPCOMING'
+  if (value === 'ACTIVE' || value === 2) return 'ACTIVE'
+  if (value === 'ENDED' || value === 3) return 'ENDED'
+  return 'DRAFT'
+}
+
+export const mapGroupStatus = (status: number | string): GroupBuyingGroup['status'] => {
+  const value = typeof status === 'string' ? status : toNumber(status)
+  if (value === 'FORMING' || value === 1) return 'FORMING'
+  if (value === 'SUCCESS' || value === 2) return 'SUCCESS'
+  if (value === 'FAILED' || value === 3) return 'FAILED'
+  return 'FORMING'
+}
+
+export const normalizeGroupBuying = (gb: Record<string, any>): GroupBuying => ({
+  id: toNumber(gb.id),
+  productId: toNumber(gb.productId),
+  productName: toString(gb.productName),
+  productImageUrl: resolveImageUrl(toString(gb.productImageUrl, '')),
+  productPrice: toNumber(gb.productPrice),
+  groupPrice: toNumber(gb.groupPrice),
+  requiredMembers: toNumber(gb.requiredMembers, 2),
+  durationMinutes: toNumber(gb.durationMinutes, 1440),
+  totalStock: toNumber(gb.totalStock),
+  remainingStock: toNumber(gb.remainingStock),
+  maxPerUser: toNumber(gb.maxPerUser, 1),
+  status: mapGroupBuyingStatus(gb.status),
+  statusDescription: toString(gb.statusDescription),
+  startTime: toIsoLikeString(gb.startTime),
+  endTime: toIsoLikeString(gb.endTime),
+  createdAt: toIsoLikeString(gb.createdAt),
+  updatedAt: toIsoLikeString(gb.updatedAt || gb.createdAt),
+  activeGroupCount: toNumber(gb.activeGroupCount),
+  discount: toNumber(gb.discount),
+})
+
+export const normalizeGroupBuyingGroup = (group: Record<string, any>): GroupBuyingGroup => ({
+  id: toNumber(group.id),
+  groupNo: toString(group.groupNo),
+  groupBuyingId: toNumber(group.groupBuyingId),
+  leaderUserId: toNumber(group.leaderUserId),
+  leaderUsername: toString(group.leaderUsername),
+  requiredMembers: toNumber(group.requiredMembers, 2),
+  currentMembers: toNumber(group.currentMembers, 1),
+  status: mapGroupStatus(group.status),
+  statusDescription: toString(group.statusDescription),
+  expireTime: toIsoLikeString(group.expireTime),
+  createdAt: toIsoLikeString(group.createdAt),
+  completedAt: group.completedAt ? toIsoLikeString(group.completedAt) : undefined,
+  members: Array.isArray(group.members)
+    ? group.members.map((m: Record<string, any>) => ({
+        id: toNumber(m.id),
+        userId: toNumber(m.userId),
+        username: toString(m.username),
+        avatar: resolveImageUrl(toString(m.avatar, '')),
+        orderId: m.orderId ? toNumber(m.orderId) : undefined,
+        status: toNumber(m.status),
+        joinedAt: toIsoLikeString(m.joinedAt),
+      }))
+    : [],
+  groupBuying: group.groupBuying ? normalizeGroupBuying(group.groupBuying) : undefined,
+})