feat: 去掉 Feed 顶栏统计并强化开源码桶

按帖子列表风格展示码桶，补齐语言/Star/Fork 与论坛作者关联回填，避免未绑定仓库与空列表。

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/components/FeedHeader.tsx

@@ -1,80 +1,41 @@
-import { Users, FileText, LayoutGrid } from 'lucide-react';
 import { useNavigate } from 'react-router-dom';
-import type { Board, ForumStats } from '../api/types';
 import { navigateFeed } from '../utils/feedCache';
 
 interface Props {
-  boardId: number;
   keyword: string;
   tag?: string;
   author?: string;
-  titleOnly?: boolean;
-  boards: Board[];
-  stats: ForumStats | null;
   postTotal: number;
   /** 搜索页用 h1；首页/板块页中间栏不再展示标题 */
   titleAs?: 'h1' | 'h2';
 }
 
 export default function FeedHeader({
-  boardId,
   keyword,
   tag = '',
   author = '',
-  boards,
-  stats,
   postTotal,
   titleAs = 'h1',
 }: Props) {
   const nav = useNavigate();
-  const board = boards.find(b => b.id === boardId);
 
   const isSearch = !!(keyword || author);
   const isTag = !!tag;
   const filtered = isSearch || isTag;
-  const inBoard = !filtered && boardId > 0 && !!board;
   const TitleTag = titleAs;
 
   let title = '';
   if (isTag) title = `标签：${tag}`;
   else if (isSearch) title = '搜索结果';
 
+  // 无标题且无操作时不占位
+  if (!filtered) return null;
+
   return (
-    <div className={`feed-head${filtered ? ' feed-head--solo' : ' feed-head--stats-only'}`}>
+    <div className="feed-head feed-head--solo">
       <div className="feed-head__title">
         {title ? <TitleTag>{title}</TitleTag> : null}
-        {!filtered && inBoard && (
-          <div className="feed-head__stats">
-            <span className="feed-stat-chip">
-              <FileText aria-hidden />
-              本板块 <strong>{postTotal}</strong> 帖
-            </span>
-            {stats && (
-              <span className="feed-stat-chip feed-stat-chip--muted" title="全站统计">
-                全站 {stats.posts} 帖 · {stats.users} 会员
-              </span>
-            )}
-          </div>
-        )}
-        {!filtered && !inBoard && stats && (
-          <div className="feed-head__stats">
-            <span className="feed-stat-chip">
-              <Users aria-hidden />
-              会员 <strong>{stats.users}</strong>
-            </span>
-            <span className="feed-stat-chip">
-              <FileText aria-hidden />
-              帖子 <strong>{stats.posts}</strong>
-            </span>
-            <span className="feed-stat-chip">
-              <LayoutGrid aria-hidden />
-              板块 <strong>{stats.boards}</strong>
-            </span>
-          </div>
-        )}
-        {filtered && (
-          <span className="feed-head__meta feed-head__meta--count">共 {postTotal} 条</span>
-        )}
+        <span className="feed-head__meta feed-head__meta--count">共 {postTotal} 条</span>
       </div>
       {isTag && (
         <button