fix(player): 评论聚焦态改为展开输入面板

test/widget_test.dart

@@ -249,8 +249,11 @@ void main() {
     await tester.pumpAndSettle();
     expect(find.text('No comments yet.'), findsOneWidget);
     await tester.enterText(find.byKey(const Key('comment-input')), 'Nice demo');
+    await tester.pump();
     await tester.tap(find.byKey(const Key('comment-post')));
     await tester.pumpAndSettle();
+    FocusManager.instance.primaryFocus?.unfocus();
+    await tester.pumpAndSettle();
     expect(find.text('Nice demo'), findsOneWidget);
     await tester.binding.handlePopRoute();
     await tester.pumpAndSettle();