fix(home): 修复频道快速切换卡 loading

test/core/data/services/home_feed_controller_test.dart

@@ -95,26 +95,109 @@ void main() {
     controller.dispose();
   });
 
-  test('should_ignore_stale_response_when_channels_switch_quickly', () async {
-    final anime = Completer<FeedPage>();
-    final live = Completer<FeedPage>();
+  test(
+    'should_cache_both_channels_when_responses_complete_out_of_order',
+    () async {
+      final anime = Completer<FeedPage>();
+      final live = Completer<FeedPage>();
+      final animeRefresh = Completer<FeedPage>();
+      final repository = _ScriptedFeedRepository()
+        ..enqueue(() => anime.future)
+        ..enqueue(() => live.future)
+        ..enqueue(() => animeRefresh.future);
+      final controller = HomeFeedController(repository);
+
+      final animeLoad = controller.selectChannel(HomeFeedChannel.anime);
+      final liveLoad = controller.selectChannel(HomeFeedChannel.live);
+      live.complete(FeedPage(dramas: [_drama('live')]));
+      await liveLoad;
+      anime.complete(FeedPage(dramas: [_drama('anime')]));
+      await animeLoad;
+
+      expect(controller.channel, HomeFeedChannel.live);
+      expect(controller.dramas.single.id, 'live');
+      await controller.selectChannel(HomeFeedChannel.anime);
+      expect(controller.dramas.single.id, 'anime');
+      animeRefresh.complete(FeedPage(dramas: [_drama('anime-refresh')]));
+      await pumpEventQueue();
+      expect(controller.dramas.single.id, 'anime-refresh');
+      controller.dispose();
+    },
+  );
+
+  test('should_retry_automatically_when_returning_to_failed_channel', () async {
     final repository = _ScriptedFeedRepository()
-      ..enqueue(() => anime.future)
-      ..enqueue(() => live.future);
+      ..enqueue(() async => throw StateError('offline'))
+      ..enqueue(() async => FeedPage(dramas: [_drama('live')]))
+      ..enqueue(() async => FeedPage(dramas: [_drama('anime-retry')]));
     final controller = HomeFeedController(repository);
 
-    final animeLoad = controller.selectChannel(HomeFeedChannel.anime);
-    final liveLoad = controller.selectChannel(HomeFeedChannel.live);
-    live.complete(FeedPage(dramas: [_drama('live')]));
-    await liveLoad;
-    anime.complete(FeedPage(dramas: [_drama('anime')]));
-    await animeLoad;
+    await controller.selectChannel(HomeFeedChannel.anime);
+    expect(controller.lastError, contains('offline'));
+    expect(controller.loadingFirstPage, isFalse);
 
-    expect(controller.channel, HomeFeedChannel.live);
-    expect(controller.dramas.single.id, 'live');
+    await controller.selectChannel(HomeFeedChannel.live);
+    await controller.selectChannel(HomeFeedChannel.anime);
+
+    expect(controller.dramas.single.id, 'anime-retry');
+    expect(repository.calls, hasLength(3));
     controller.dispose();
   });
 
+  test('should_not_report_first_page_loading_without_inflight_request', () {
+    final controller = HomeFeedController(_ScriptedFeedRepository());
+
+    expect(controller.loaded, isFalse);
+    expect(controller.loadingFirstPage, isFalse);
+    controller.dispose();
+  });
+
+  test('should_finish_loading_with_error_when_request_times_out', () async {
+    final pending = Completer<FeedPage>();
+    final repository = _ScriptedFeedRepository()..enqueue(() => pending.future);
+    final controller = HomeFeedController(
+      repository,
+      requestTimeout: const Duration(milliseconds: 10),
+    );
+
+    await controller.selectChannel(HomeFeedChannel.anime);
+
+    expect(controller.loadingFirstPage, isFalse);
+    expect(controller.loaded, isTrue);
+    expect(controller.lastError, isNotNull);
+    controller.dispose();
+  });
+
+  test(
+    'should_ignore_old_failure_when_same_channel_new_request_succeeds',
+    () async {
+      final oldRefresh = Completer<FeedPage>();
+      final repository = _ScriptedFeedRepository()
+        ..enqueue(
+          () async => FeedPage(
+            dramas: [_drama('a')],
+            nextCursor: 'next',
+            hasMore: true,
+          ),
+        )
+        ..enqueue(() async => FeedPage(dramas: [_drama('live')]))
+        ..enqueue(() => oldRefresh.future)
+        ..enqueue(() async => FeedPage(dramas: [_drama('b')], hasMore: false));
+      final controller = HomeFeedController(repository);
+      await controller.selectChannel(HomeFeedChannel.anime);
+      await controller.selectChannel(HomeFeedChannel.live);
+      await controller.selectChannel(HomeFeedChannel.anime);
+
+      await controller.loadMore();
+      oldRefresh.completeError(StateError('old failure'));
+      await pumpEventQueue();
+
+      expect(controller.dramas.map((drama) => drama.id), ['a', 'b']);
+      expect(controller.lastError, isNull);
+      controller.dispose();
+    },
+  );
+
   test('should_keep_old_data_when_refresh_fails', () async {
     final repository = _ScriptedFeedRepository()
       ..enqueue(() async => FeedPage(dramas: [_drama('old')]))