[CoR] Todos list shows "Open embedded plan view" as incomplete even when Project Plan view is already open

[v-ruizh]

OS: Win11 x64
VS Code Insider: 1.133.0-insider
Build Version: 0.12.8-alpha.0

Repro Steps:

1. Open an empty folder.
2. In Azure Project view, click "Create New Project with Copilot".
3. Enter a project description: a to-do list web app with a REST API and a database
4. Wait for the project plan to be generated.
5. Open the embedded Project Plan view.
6. Observe the Todos list.

Expect:

• Once the embedded Project Plan view is opened, the corresponding Todos item should be automatically marked as completed.
• The Todos list should accurately reflect the current workflow/UI state.

Actual:

• The Project Plan view is already open and visible.
• The Todos list still shows "Open embedded plan view" as an incomplete task.