Show the active environment directory after switching a thread workspace

[smsunarto]

Summary

After update_environment_directory switches a thread to another directory, the composer footer continues to show the original project name. The thread uses the new directory correctly, but the UI makes it appear that the switch failed.

Reproduction

1. Start a thread in project project-a.
2. Call update_environment_directory with /path/to/project-b.
3. Send another message so the provider starts in the new environment.
4. Check the workspace label in the composer footer.

Current behavior

The environment is updated correctly:

• environment.path is /path/to/project-b.
• The branch and working-tree summary come from project-b.
• The thread still has the project-a project ID.
• The footer shows only project-a.

This creates conflicting UI signals. The branch and diff belong to project-b, while the adjacent folder label says project-a.

Expected behavior

When the active environment path differs from the project root, the composer footer should show the active workspace directory:

project-a / project-b

The full environment path should be available in a tooltip:

/path/to/project-b

The UI should update as soon as the thread environment changes. It should not require a page reload.