feat(app): 完善播放协议搜索与空状态

test/player/double_tap_like_test.dart

@@ -12,8 +12,8 @@ import '../support/fake_haptics.dart';
 import '../support/fake_interaction_repositories.dart';
 
 void main() {
-  testWidgets('double tap within 320ms never pauses', (tester) async {
-    for (final delay in [120, 250, 300]) {
+  testWidgets('double tap within 400ms never pauses', (tester) async {
+    for (final delay in [120, 250, 300, 380]) {
       final repository = FakeInteractionRepository();
       final haptics = FakeHaptics();
       final key = GlobalKey<_HarnessState>();