As a user, I want to track changes and access previous versions of the proposal so that I can review the history and revert to earlier versions if needed.

* The system tracks all changes made to the proposal.

* Users can access a history of changes with timestamps and user information.

* Previous versions of the proposal are saved and can be restored.

* Users can compare different versions to see what has changed.

* The system highlights changes between versions.

* Notifications are sent when a new version is saved.

* Users can add comments or notes to specific versions.