fix(player): 优化加载指示器与锁定进度条

test/playback/seek_progress_bar_test.dart

@@ -2,6 +2,7 @@
 
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
+import 'package:fruitshorts/core/theme/app_colors.dart';
 import 'package:fruitshorts/pages/player/widgets/seek_progress_bar.dart';
 import 'package:video_player/video_player.dart';
 
@@ -34,6 +35,47 @@ void main() {
     expect(find.byType(Slider), findsNothing);
   });
 
+  testWidgets('should_show_inactive_track_and_disable_seek_when_locked', (
+    tester,
+  ) async {
+    final video = ValueNotifier<VideoPlayerValue>(
+      const VideoPlayerValue(
+        duration: Duration(seconds: 12),
+        position: Duration(seconds: 3),
+        isInitialized: true,
+      ),
+    );
+    addTearDown(video.dispose);
+    var seeks = 0;
+    await tester.pumpWidget(
+      MaterialApp(
+        home: Scaffold(
+          body: SeekProgressBar(
+            valueListenable: video,
+            semanticsLabel: 'Seek video',
+            locked: true,
+            onSeek: (_) async => seeks++,
+          ),
+        ),
+      ),
+    );
+
+    expect(find.byKey(const Key('progress-loading')), findsNothing);
+    expect(find.byKey(const Key('progress-loading-highlight')), findsNothing);
+    expect(find.byType(Slider), findsNothing);
+    final inactive = tester.widget<ColoredBox>(
+      find.byKey(const Key('progress-inactive')),
+    );
+    expect(inactive.color, AppColors.border);
+
+    await tester.drag(
+      find.byKey(const Key('progress-inactive')),
+      const Offset(120, 0),
+    );
+    await tester.pumpAndSettle();
+    expect(seeks, 0);
+  });
+
   testWidgets('should_debounce_buffering_before_showing_loading_track', (
     tester,
   ) async {