Unexpected Inspector behavior with package roots

In this screenshot:

- I am running the `standalone_ui/editor_sidebar` run configuration in the devtools_app project.
- I used the inspector & select widget mode to select the column in the mock editor (from `mock_editor_widget.dart`)
- In the summary tree, nothing below the `SizedBox` widget from the `SplitPane` is present.
- In the details tree, the Column I have selected is present.
- The `mock_editor_widget.dart` file exists under `devtools_app/test/` and one of the pub root directories is `/Users/path/to/devtools_app`, so widgets created in this location should be included in the summary tree.


从 standalone_ui/editor_sidebar 运行配置开始，并使用 inspector 的 select widget mode 重现该问题。比较 test/mock_editor_widget.dart 中 Column 的 summary 树和 details 树，然后跟踪 pub root 目录如何确定哪些 widgets 出现在 summary 树中。完成标准是：列出的 devtools_app pub root 下的 widgets 始终被一致地包含。

由索引模型根据 Issue 内容生成。