xhs_get_comments 增加 sort + max_count 控制，评论随详情一起返回

- Comment 新增 subCommentCount，新增 CommentsResult 接口
- GetFeedCommentsSchema 替换 load_all 为 sort (default/newest/most_liked) + max_count (1-100)
- getFeedDetail 不再清空评论，从 Vue store 异步提取首屏评论（轮询 firstRequestFinish）
- getFeedComments 重写：支持排序切换、按 maxCount 加载、返回 hasMore/totalCount
- 前端详情加载后直接显示评论，无需单独请求；底部显示"加载更多评论"按钮
- CommentTree 显示"还有 X 条回复"提示
- 修复 formatTime 对空字符串和无效日期的处理

web/src/components/feed/FeedDetail.tsx

@@ -1,6 +1,6 @@
 import { useState, useEffect } from 'react';
-import type { FeedDetail as FeedDetailType } from '@/api/types';
-import { getFeedDetail, toggleLike, toggleFavorite, postComment, replyComment } from '@/api/endpoints';
+import type { FeedDetail as FeedDetailType, Comment } from '@/api/types';
+import { getFeedDetail, getFeedComments, toggleLike, toggleFavorite, postComment, replyComment } from '@/api/endpoints';
 import { Badge } from '@/components/ui/Badge';
 import { Spinner } from '@/components/ui/Spinner';
 import { Button } from '@/components/ui/Button';
@@ -23,6 +23,12 @@ export function FeedDetail({ feedId, xsecToken, onClose, onUserClick }: Props) {
   const [error, setError] = useState<string | null>(null);
   const [currentImage, setCurrentImage] = useState(0);
 
+  const [comments, setComments] = useState<Comment[]>([]);
+  const [commentsLoading, setCommentsLoading] = useState(false);
+  const [commentsHasMore, setCommentsHasMore] = useState(false);
+  const [commentsTotalCount, setCommentsTotalCount] = useState(0);
+  const [commentsMaxCount, setCommentsMaxCount] = useState(20);
+
   const [liked, setLiked] = useState(false);
   const [favorited, setFavorited] = useState(false);
   const [actionLoading, setActionLoading] = useState<string | null>(null);
@@ -33,20 +39,50 @@ export function FeedDetail({ feedId, xsecToken, onClose, onUserClick }: Props) {
   useEffect(() => {
     setLoading(true);
     setError(null);
+    setComments([]);
     void getFeedDetail(feedId, xsecToken)
       .then((res) => {
         if (res.success && res.data) {
           setDetail(res.data);
           setLiked(res.data.isLiked);
           setFavorited(res.data.isFavorited);
+          // Use comments from __INITIAL_STATE__ (first page, ~10-20).
+          if (res.data.comments.length > 0) {
+            setComments(res.data.comments);
+            setCommentsTotalCount(res.data.commentCount);
+            setCommentsHasMore(res.data.commentCount > res.data.comments.length);
+          }
         } else {
           setError(res.error?.message || 'Failed to load detail');
         }
       })
       .catch((err) => setError(err instanceof Error ? err.message : 'Error'))
       .finally(() => setLoading(false));
+
   }, [feedId, xsecToken]);
 
+  const handleLoadComments = async (maxCount = commentsMaxCount) => {
+    setCommentsLoading(true);
+    try {
+      const res = await getFeedComments(feedId, xsecToken, 'default', maxCount);
+      if (res.success && res.data) {
+        setComments(res.data.comments);
+        setCommentsHasMore(res.data.hasMore);
+        setCommentsTotalCount(res.data.totalCount);
+      }
+    } catch {
+      toast('error', '加载评论失败');
+    } finally {
+      setCommentsLoading(false);
+    }
+  };
+
+  const handleLoadMore = () => {
+    const nextCount = commentsMaxCount * 2;
+    setCommentsMaxCount(nextCount);
+    void handleLoadComments(nextCount);
+  };
+
   const handleToggleLike = async () => {
     setActionLoading('like');
     try {
@@ -232,7 +268,7 @@ export function FeedDetail({ feedId, xsecToken, onClose, onUserClick }: Props) {
               )}
               <div>
                 <p className="text-sm font-medium">{detail.user.nickname}</p>
-                <p className="text-xs text-dark-muted">{detail.ipLocation} · {formatTime(detail.createTime)}</p>
+                <p className="text-xs text-dark-muted">{[detail.ipLocation, formatTime(detail.createTime)].filter(Boolean).join(' · ') || '暂无信息'}</p>
               </div>
             </div>
 
@@ -287,18 +323,43 @@ export function FeedDetail({ feedId, xsecToken, onClose, onUserClick }: Props) {
             </div>
 
             {/* Comments */}
-            {detail.comments.length > 0 && (
+            {comments.length === 0 && !commentsLoading && (
+              <Button
+                size="sm"
+                variant="secondary"
+                onClick={() => void handleLoadComments()}
+              >
+                加载评论
+              </Button>
+            )}
+            {commentsLoading && (
+              <div className="flex items-center gap-2 py-4 text-dark-muted text-sm">
+                <Spinner size="sm" />
+                <span>加载评论中...</span>
+              </div>
+            )}
+            {comments.length > 0 && (
               <div>
                 <h3 className="text-sm font-semibold text-dark-muted uppercase tracking-wider mb-3">
-                  评论 ({detail.comments.length})
+                  评论 ({commentsTotalCount > 0 ? commentsTotalCount : comments.length})
                 </h3>
                 <CommentTree
-                  comments={detail.comments}
+                  comments={comments}
                   onReply={(commentId, userId, nickname) => {
                     setReplyTarget({ commentId, userId, nickname });
                     setReplyText('');
                   }}
                 />
+                {commentsHasMore && !commentsLoading && (
+                  <Button
+                    size="sm"
+                    variant="secondary"
+                    onClick={handleLoadMore}
+                    className="mt-3 w-full"
+                  >
+                    加载更多评论
+                  </Button>
+                )}
               </div>
             )}
           </div>