新增评论通知功能：MCP工具 + REST端点 + 前端通知面板

- 新增 xhs_get_comment_notifications / xhs_reply_notification MCP工具
- 通知获取前先读取首页未读小红点数字，无未读则直接返回空，避免重复处理
- 新增 REST 端点 GET /notifications/comments 和 POST /notifications/reply
- 前端小红书页面新增「通知」按钮和 NotificationPanel slide-over 组件
- 通知面板支持查看评论通知列表和行内回复

web/src/api/endpoints.ts

@@ -11,6 +11,7 @@ import type {
   ApiResponse,
   PublishResult,
   CommentResult,
+  CommentNotification,
 } from './types';
 
 // Health (no auth required)
@@ -112,6 +113,20 @@ export const replyComment = (data: {
     body: JSON.stringify(data),
   });
 
+// Notifications
+export const getCommentNotifications = (maxCount = 20) =>
+  apiFetch<ApiResponse<CommentNotification[]>>(`/api/xhs/notifications/comments?max_count=${maxCount}`);
+
+export const replyNotification = (data: {
+  user_id: string;
+  comment_content: string;
+  reply_content: string;
+}) =>
+  apiFetch<ApiResponse<CommentResult>>('/api/xhs/notifications/reply', {
+    method: 'POST',
+    body: JSON.stringify(data),
+  });
+
 export const toggleLike = (feedId: string, xsecToken: string) =>
   apiFetch<ApiResponse<{ success: boolean; liked: boolean }>>('/api/xhs/like', {
     method: 'POST',