feat(app): 完善播放协议搜索与空状态

test/comment/drama_comments_sheet_test.dart

@@ -431,6 +431,11 @@ void main() {
     final successText = tester.widget<Text>(find.text('发表成功'));
     expect(successText.style?.color, Colors.white);
     expect(successText.style?.fontSize, 14);
+    expect(successText.style?.decoration, TextDecoration.none);
+    final screen = tester.view.physicalSize / tester.view.devicePixelRatio;
+    final toast = tester.getRect(successOverlay);
+    expect(toast.center.dy, lessThan(screen.height * 0.4));
+    expect(toast.center.dy, greaterThan(screen.height * 0.2));
     final placeholderRect = tester.getRect(
       find.byKey(const Key('comment-input-placeholder')),
     );