fix: improve reservation cleanup and share popup handling

backend/server.js

@@ -8843,7 +8843,10 @@ app.post('/api/admin/download-reservations/:id/cancel', authMiddleware, adminMid
 // 下载流量预扣运维面板：批量清理（过期 pending + 历史 finalized）
 app.post('/api/admin/download-reservations/cleanup', authMiddleware, adminMiddleware, (req, res) => {
   try {
-    const keepDays = Math.min(365, Math.max(1, parseInt(req.body?.keep_days, 10) || 7));
+    // 默认 keep_days=0：立即清理全部已完成历史记录，避免“清理无效果”的感知
+    const rawKeepDays = req.body?.keep_days;
+    const parsedKeepDays = Number.isFinite(Number(rawKeepDays)) ? parseInt(rawKeepDays, 10) : 0;
+    const keepDays = Math.min(365, Math.max(0, Number.isFinite(parsedKeepDays) ? parsedKeepDays : 0));
     const expireResult = DownloadTrafficReservationDB.expirePendingReservations();
     const cleanupResult = DownloadTrafficReservationDB.cleanupFinalizedHistory(keepDays);
 
@@ -8860,7 +8863,7 @@ app.post('/api/admin/download-reservations/cleanup', authMiddleware, adminMiddle
 
     res.json({
       success: true,
-      message: '预扣清理完成',
+      message: `预扣清理完成（过期待确认 ${Number(expireResult?.changes || 0)} 条，删除历史 ${Number(cleanupResult?.changes || 0)} 条）`,
       result: {
         keep_days: keepDays,
         expired_pending: Number(expireResult?.changes || 0),