diff --git a/backend/server.js b/backend/server.js
index af91709..39a3c25 100644
--- a/backend/server.js
+++ b/backend/server.js
@@ -335,7 +335,8 @@ app.get('/api/packages', (req, res) => {
   const demo = isDemoMode()
   const storage = currentStorage()
   const validation = demo ? { ok: true, message: 'demo' } : validateStorage(storage)
-  const packages = buildPackages(req.query.keyword || '') // 先构建（触发懒扫描并填充缓存）
+  ensureScan() // 懒触发：登录后首次拉包自动启动扫描（rawCache 缺失时），返回 scanning 状态供前端轮询
+  const packages = buildPackages(req.query.keyword || '') // 先构建（填充缓存）
   res.json({
     demo,
     storageDir: storage || null,