feat(flutter): 增加 debug 服务地址编辑器

test/discover/home_all_dramas_grid_test.dart

@@ -137,6 +137,10 @@ void main() {
     expect(find.text('Retry'), findsOneWidget);
     expect(find.byKey(const Key('catalog-debug-endpoint')), findsOneWidget);
     expect(find.byKey(const Key('catalog-debug-error')), findsOneWidget);
+    expect(
+      find.byKey(const Key('catalog-debug-endpoint-edit')),
+      findsOneWidget,
+    );
     expect(find.textContaining('discover feed unavailable'), findsOneWidget);
   });