Can a project be restored?

The project cannot be restored. Once deleted, it is not going to be reflected in the Recycle Bin. In this case, you must create it again and link the documents of the deleted one.

Bear in mind, that even if you delete a project, you can always view it through the "More information" section of those documents that were related to the deleted project.

That is, you can access an invoice, for example, that was related to the project, click on More information and thus view the project again. Once you have done this, you can create a new project in which you can replicate everything you had in the deleted project.