feat: 核心股页面补最近上榜日期列

Co-Authored-By: Claude <noreply@anthropic.com>

src/routes/core-stocks.tsx

@@ -69,6 +69,7 @@ function CoreStocksPage() {
                     </th>
                   ))}
                   <th scope="col" className="px-2 py-2 text-right font-medium" title="覆盖题材数">题材数</th>
+                  <th scope="col" className="px-2 py-2 text-right font-medium whitespace-nowrap">最近上榜</th>
                   <th scope="col" className="px-2 py-2 text-right font-medium">上榜</th>
                 </tr>
               </thead>
@@ -91,6 +92,9 @@ function CoreStocksPage() {
                     <td className="px-2 py-1.5 text-right tabular-nums whitespace-nowrap text-muted-foreground">
                       {s.coverCount ?? "·"}
                     </td>
+                    <td className="px-2 py-1.5 text-right tabular-nums whitespace-nowrap text-muted-foreground">
+                      {s.lastAppear ? s.lastAppear.slice(5) : "·"}
+                    </td>
                     <td className="px-2 py-1.5 text-right tabular-nums whitespace-nowrap">
                       <span className="inline-flex items-center gap-0.5 text-orange-500">
                         <Flame className="h-3 w-3" />