fix(ui): 修正六屏顶栏与内容间距

test/discover/home_all_dramas_grid_test.dart

@@ -39,6 +39,23 @@ void main() {
 
       expect(find.text('Continue Watching'), findsNothing);
       expect(find.text('Recommended'), findsOneWidget);
+      for (final key in const [
+        Key('discover-search-button'),
+        Key('discover-profile'),
+      ]) {
+        expect(tester.getSize(find.byKey(key)), const Size(36, 36));
+        expect(
+          tester
+              .widget<Icon>(
+                find.descendant(
+                  of: find.byKey(key),
+                  matching: find.byType(Icon),
+                ),
+              )
+              .size,
+          18,
+        );
+      }
       expect(find.text('For You'), findsNothing);
       final grid = tester.widget<SliverGrid>(
         find.byKey(const Key('home-all-dramas-grid')),