fix: 切换/删除账号时清空视频缓存，防止看到已删除账号的视频

apps/macos/VODManager/Sources/VODManager/Views/VideoListView.swift

@@ -1,6 +1,7 @@
 import SwiftUI
 
 struct VideoListView: View {
+    @EnvironmentObject var accountStore: AccountStore
     @State private var allVideos: [VideoItem] = []
     @State private var filteredVideos: [VideoItem] = []
     @State private var displayVideos: [VideoItem] = []
@@ -210,6 +211,14 @@ struct VideoListView: View {
                 await refreshFromAPI()
             }
         }
+        .onChange(of: accountStore.activeAccount?.id) { _, newId in
+            allVideos = []
+            filteredVideos = []
+            displayVideos = []
+            selectedVideos = []
+            errorMessage = nil
+            Task { await refreshFromAPI() }
+        }
         .sheet(isPresented: $showDownloadPanel) {
             DownloadPanelView(items: downloadResults)
         }