Undo File Changes action has no effect in an agent session

Type: Bug

When using the **Undo File Changes** action for an agent session, the action appears to do nothing: the changed files remain unchanged and there is no visible error or feedback.

Steps to reproduce:

1. Open an agent session that has made file changes.
2. Invoke **Undo File Changes**.
3. Observe that the file changes are not reverted.

Expected behavior:

The changes made by the agent are reverted, or an actionable error is shown if they cannot be reverted.

Actual behavior:

Nothing visible happens and the file changes remain.

A screen recording was included with the original report in Slack. Version, OS, session provider, and logs were not included in the report.