fix(player): 修正缓冲态与首帧时间闪现

test/player/player_fullscreen_test.dart

@@ -361,7 +361,11 @@ void main() {
       findsOneWidget,
     );
     expect(find.byKey(const Key('player-progress')), findsOneWidget);
-    expect(find.text('00:00 / 01:00'), findsOneWidget);
+    expect(
+      find.byKey(const Key('player-progress-uninitialized-time')),
+      findsNothing,
+    );
+    expect(find.text('00:00 / 01:00'), findsNothing);
 
     // IgnorePointer 让加载中的播放暂停与上下滑穿透，滑动会关闭入口 loading。
     expect(fullLogic.session.userWantsPlay, isTrue);
@@ -515,6 +519,49 @@ void main() {
     expect(find.byKey(const Key('progress-inactive')), findsOneWidget);
   });
 
+  testWidgets('should_only_show_progress_buffer_after_video_first_frame', (
+    tester,
+  ) async {
+    final factory = _RouteVideoFactory();
+    await _pumpApp(tester, playerFactory: factory.create);
+    await _openSeriesPlayer(tester);
+
+    final videoIndex = factory.episodes.lastIndexWhere(
+      (episode) => episode.id == 'city-lights-demo-1',
+    );
+    final video = factory.created[videoIndex];
+    expect(video.controller.value.isInitialized, isTrue);
+    expect(find.byKey(const Key('player-entry-loading-overlay')), findsNothing);
+
+    video.controller.value = const VideoPlayerValue(
+      duration: Duration(minutes: 1),
+      size: Size(1280, 720),
+      position: Duration(seconds: 5),
+      isInitialized: true,
+      isPlaying: true,
+      isBuffering: true,
+    );
+    await tester.pump(const Duration(milliseconds: 400));
+
+    expect(find.byKey(const Key('progress-loading')), findsOneWidget);
+    expect(find.byKey(const Key('player-entry-loading-overlay')), findsNothing);
+    expect(find.byKey(const Key('player-video-loading')), findsNothing);
+    expect(find.byKey(const Key('player-ticket-loading')), findsNothing);
+
+    video.controller.value = const VideoPlayerValue(
+      duration: Duration(minutes: 1),
+      size: Size(1280, 720),
+      position: Duration(seconds: 6),
+      isInitialized: true,
+      isPlaying: true,
+      isBuffering: true,
+    );
+    await tester.pump();
+
+    expect(find.byKey(const Key('progress-loading')), findsNothing);
+    expect(find.byType(Slider), findsOneWidget);
+  });
+
   testWidgets('should_pause_feed_when_auth_page_is_pushed_and_resume_on_pop', (
     tester,
   ) async {