feat(flutter): 统一二级页头并恢复新剧暖色

test/mine/settings_page_test.dart

@@ -52,6 +52,13 @@ void main() {
     await tester.pumpAndSettle();
 
     expect(find.byKey(const Key('settings-page')), findsOneWidget);
+    expect(
+      tester.getSize(find.byKey(const Key('settings-back'))),
+      const Size(36, 36),
+    );
+    final title = tester.widget<Text>(find.byKey(const Key('subpage-title')));
+    expect(title.style?.fontSize, 18);
+    expect(title.style?.fontWeight, FontWeight.w800);
     expect(find.byKey(const Key('settings-notices')), findsOneWidget);
     expect(find.byKey(const Key('server-endpoint-setting')), findsNothing);
     expect(find.text('Server address'), findsNothing);