feat(album): add pull-to-refresh to album entry

suixinkan/Features/TravelAlbum/ViewModels/TravelAlbumEntryViewModel.swift

@@ -52,7 +52,10 @@ final class TravelAlbumEntryViewModel {
     }
 
     /// 重新拉取相册列表。
-    func loadAlbums(api: any TravelAlbumServing) async {
+    func loadAlbums(
+        api: any TravelAlbumServing,
+        preservingContentOnFailure: Bool = false
+    ) async {
         isLoading = true
         notifyStateChange()
         defer {
@@ -67,12 +70,20 @@ final class TravelAlbumEntryViewModel {
         } catch is CancellationError {
             return
         } catch {
-            albums = []
-            albumTotal = 0
+            if !preservingContentOnFailure {
+                albums = []
+                albumTotal = 0
+            }
             onShowMessage?(error.localizedDescription)
         }
     }
 
+    /// 用户下拉刷新相册列表；失败时保留当前内容，避免页面瞬间清空。
+    func refreshAlbums(api: any TravelAlbumServing) async {
+        guard !isLoading else { return }
+        await loadAlbums(api: api, preservingContentOnFailure: true)
+    }
+
     /// 打开创建相册弹窗。
     func openCreateSheet(api: any TravelAlbumServing) async {
         guard !isCreating else { return }