feat: 可选社区上报与官方精选展柜

默认关闭，仪表盘一键开关；枢纽由运维配置收报，人工精选后展示于 /showcase。

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

frontend/src/pages/admin/AdminCommunityPage.tsx

@@ -0,0 +1,159 @@
+import { useEffect, useState } from 'react';
+import { Link } from 'react-router-dom';
+import { Globe2, ExternalLink, Star } from 'lucide-react';
+import { Spinner } from '@/components/ui/spinner';
+import { Badge } from '@/components/ui/badge';
+import { Button } from '@/components/ui/button';
+import { notify } from '@/lib/notify';
+import { api } from '../../api/client';
+import type { CommunityInstance } from '../../api/types';
+import { useAdminGuard } from '../../layouts/AdminLayout';
+import { formatTime } from '../../utils/content';
+import { cn } from '@/lib/utils';
+
+export default function AdminCommunityPage() {
+  const { ready } = useAdminGuard();
+  const [hubEnabled, setHubEnabled] = useState(false);
+  const [list, setList] = useState<CommunityInstance[]>([]);
+  const [loading, setLoading] = useState(true);
+  const [featuringId, setFeaturingId] = useState<string | null>(null);
+
+  useEffect(() => {
+    if (!ready) return;
+    setLoading(true);
+    api.adminCommunityInstances()
+      .then((r) => {
+        setHubEnabled(!!r.hub_enabled);
+        setList(Array.isArray(r.instances) ? r.instances : []);
+      })
+      .catch(() => {
+        setList([]);
+      })
+      .finally(() => setLoading(false));
+  }, [ready]);
+
+  const handleToggleFeatured = async (row: CommunityInstance) => {
+    if (featuringId) return;
+    setFeaturingId(row.instance_id);
+    try {
+      const r = await api.adminFeatureCommunityInstance(row.instance_id, {
+        featured: !row.featured,
+        featured_note: row.featured_note || '',
+      });
+      setList((prev) => prev.map((item) => (
+        item.instance_id === row.instance_id ? { ...item, ...r.instance } : item
+      )));
+      notify.success(r.message);
+    } catch (e: unknown) {
+      notify.error(e instanceof Error ? e.message : '操作失败');
+    } finally {
+      setFeaturingId(null);
+    }
+  };
+
+  if (!ready || loading) {
+    return <div className="flex justify-center py-16"><Spinner size="lg" /></div>;
+  }
+
+  return (
+    <div className="admin-page">
+      <div className="admin-page-head">
+        <div>
+          <h1 className="admin-page-title">
+            <Globe2 size={22} aria-hidden />
+            公网实例
+          </h1>
+          <p className="admin-page-desc">
+            接收自愿上报的心跳；设为精选后会出现在
+            {' '}
+            <Link to="/showcase" className="admin-inline-link" target="_blank" rel="noopener noreferrer">公开展柜</Link>
+          </p>
+        </div>
+      </div>
+
+      {!hubEnabled && (
+        <div className="admin-card admin-settings-card" style={{ marginBottom: 16 }}>
+          <div className="admin-card-body">
+            <p>
+              本站未开启社区枢纽。该能力仅供官方主站运维配置开启（
+              <code>app.ini</code> 的 <code>[community] hub = true</code>
+              {' '}或环境变量 <code>JIANG13_COMMUNITY_HUB=1</code>
+              ），普通部署无需也无法在后台打开。
+            </p>
+          </div>
+        </div>
+      )}
+
+      <div className="admin-card">
+        <div className="admin-card-head">
+          <span>实例列表</span>
+          <span className="admin-settings-card-badge">{list.length} 个</span>
+        </div>
+        <div className="admin-card-body" style={{ padding: 0 }}>
+          {list.length === 0 ? (
+            <p className="admin-empty" style={{ padding: 24 }}>暂无上报记录</p>
+          ) : (
+            <div className="admin-table-wrap">
+              <table className="admin-table">
+                <thead>
+                  <tr>
+                    <th>状态</th>
+                    <th>站点</th>
+                    <th>版本</th>
+                    <th>用户</th>
+                    <th>帖子</th>
+                    <th>最近心跳</th>
+                    <th>精选</th>
+                  </tr>
+                </thead>
+                <tbody>
+                  {list.map((row) => (
+                    <tr key={row.instance_id}>
+                      <td>
+                        <Badge variant={row.online ? 'default' : 'secondary'}>
+                          {row.online ? '在线' : '离线'}
+                        </Badge>
+                      </td>
+                      <td>
+                        <div className="admin-community-site">
+                          <strong>
+                            {row.featured && <Star size={12} className="admin-community-star" aria-hidden />}
+                            {row.site_name || '未命名站点'}
+                          </strong>
+                          <a
+                            href={row.site_url}
+                            target="_blank"
+                            rel="noopener noreferrer"
+                            className={cn('admin-inline-link', 'admin-community-url')}
+                          >
+                            {row.site_url}
+                            <ExternalLink size={12} aria-hidden />
+                          </a>
+                        </div>
+                      </td>
+                      <td><code>{row.version || '—'}</code></td>
+                      <td>{row.users}</td>
+                      <td>{row.posts}</td>
+                      <td title={row.last_seen_at}>{formatTime(row.last_seen_at)}</td>
+                      <td>
+                        <Button
+                          variant="outline"
+                          size="sm"
+                          loading={featuringId === row.instance_id}
+                          disabled={!!featuringId}
+                          onClick={() => void handleToggleFeatured(row)}
+                        >
+                          {row.featured ? '取消精选' : '精选'}
+                        </Button>
+                      </td>
+                    </tr>
+                  ))}
+                </tbody>
+              </table>
+            </div>
+          )}
+        </div>
+      </div>
+    </div>
+  );
+}