fix: label citation links by their actual target

frontend/src/Chat.tsx

@@ -84,6 +84,17 @@ const safeUrl = (raw: unknown) => {
   try { const url = new URL(raw, window.location.origin); return ['http:', 'https:'].includes(url.protocol) ? url.href : undefined; }
   catch { return undefined; }
 };
+const isImageUrl = (href: string) => {
+  const path = new URL(href).pathname;
+  return /^\/api\/assets\/\d+\/\d+\/?$/.test(path) || /\.(?:png|jpe?g|gif|webp|avif|svg)$/i.test(path);
+};
+const sourceLabel = (href: string) => {
+  const url = new URL(href);
+  if (isImageUrl(href)) return '查看图像';
+  if (/^\/api\/knowledge\/documents\/\d+\/pages\/\d+\/?$/.test(url.pathname)) return '查看页面文字';
+  if (url.pathname === '/' && url.searchParams.get('page') === 'scores') return '查看评分';
+  return '打开来源';
+};
 function Answer({ text }: { text: string }) {
   return <div className="chat-markdown"><ReactMarkdown remarkPlugins={[remarkGfm]} urlTransform={url => safeUrl(url) || ''}
     components={{ a: ({ href, children }) => safeUrl(href) ? <a href={safeUrl(href)} target="_blank" rel="noopener noreferrer">{children}</a> : <span>{children}</span>,
@@ -94,10 +105,12 @@ function CitationCards({ items }: { items: any[] }) {
   return <div className="citation-grid">{items.map((item: any, index) => { const name = String(item.title || item.document || '未命名资料');
     const page = item.page ?? item.slide; const place = page == null ? '' : `第 ${page} ${/\.pptx?$/i.test(name) ? '张幻灯片' : '页'}`;
     const quote = typeof item.quote === 'string' ? item.quote.trim() : '';
+    const sourceHref = safeUrl(item.url);
+    const imageHref = safeUrl(item.image_url);
     return <div className="citation-card" key={`${name}-${page}-${index}`}><div className="citation-heading"><Text strong>{name}</Text>{place && <Tag>{place}</Tag>}</div>
       {quote && (quote.length > 320 ? <details><summary>{quote.slice(0, 240)}… 展开原文</summary><p>{quote}</p></details> : <p>{quote}</p>)}
-      <Space wrap size="small">{safeUrl(item.url) && <a href={safeUrl(item.url)} target="_blank" rel="noopener noreferrer">打开页面</a>}
-        {safeUrl(item.image_url) && <a href={safeUrl(item.image_url)} target="_blank" rel="noopener noreferrer">查看图像</a>}</Space></div>;
+      <Space wrap size="small">{sourceHref && <a href={sourceHref} target="_blank" rel="noopener noreferrer">{sourceLabel(sourceHref)}</a>}
+        {imageHref && imageHref !== sourceHref && <a href={imageHref} target="_blank" rel="noopener noreferrer">查看图像</a>}</Space></div>;
   })}</div>;
 }
 function Citations({ items }: { items: any[] }) {