fix(player): 延长飘心并显示毫秒计时

test/player/player_double_tap_hearts_test.dart

@@ -19,6 +19,11 @@ void main() {
     expect(_size(tester, 0), 48);
     expect(_size(tester, 1), 36);
     expect(_size(tester, 2), 40);
+    final elapsedText = tester
+        .widget<Text>(find.byKey(const Key('heart-burst-elapsed-debug')))
+        .data!;
+    final elapsedMs = int.parse(elapsedText.replaceFirst('ms', ''));
+    expect(elapsedMs, inInclusiveRange(180, 220));
     expect(
       tester
           .widgetList<Stack>(
@@ -32,7 +37,23 @@ void main() {
     );
   });
 
-  testWidgets('develop heart burst completes after about 770ms', (
+  testWidgets('heart burst keeps opacity then fades after 55 percent', (
+    tester,
+  ) async {
+    await tester.pumpWidget(
+      const MaterialApp(
+        home: Scaffold(body: PlayerDoubleTapHeartBurst(onCompleted: _noop)),
+      ),
+    );
+
+    await tester.pump(const Duration(milliseconds: 450));
+    expect(_opacity(tester, 0), closeTo(1, 1e-9));
+
+    await tester.pump(const Duration(milliseconds: 750));
+    expect(_opacity(tester, 0), lessThan(0.5));
+  });
+
+  testWidgets('develop heart burst completes after about 1590ms', (
     tester,
   ) async {
     var completed = false;
@@ -45,14 +66,14 @@ void main() {
       ),
     );
 
-    while (!completed && elapsedMs < 1200) {
+    while (!completed && elapsedMs < 2000) {
       await tester.pump(const Duration(milliseconds: 16));
       elapsedMs += 16;
     }
 
     expect(completed, isTrue);
-    expect(elapsedMs, greaterThanOrEqualTo(752));
-    expect(elapsedMs, lessThanOrEqualTo(800));
+    expect(elapsedMs, greaterThanOrEqualTo(1584));
+    expect(elapsedMs, lessThanOrEqualTo(1616));
   });
 }
 
@@ -60,4 +81,14 @@ double _size(WidgetTester tester, int index) {
   return tester.widget<Icon>(find.byKey(Key('double-tap-heart-$index'))).size!;
 }
 
+double _opacity(WidgetTester tester, int index) {
+  final opacity = find
+      .ancestor(
+        of: find.byKey(Key('double-tap-heart-$index')),
+        matching: find.byType(Opacity),
+      )
+      .first;
+  return tester.widget<Opacity>(opacity).opacity;
+}
+
 void _noop() {}