Restrict access to next step in the navigation bar.

Restrict an access to next step in the navigation bar if user didn't change or enter their own data.
Right now you can skip steps by clicking in navigation bar and get results without entering any data.

Start by reproducing the issue in the navigation bar: click ahead without changing or entering data and confirm that later results are shown. Trace the navigation and step-validation entry points, then verify that advancing is blocked until the user's data is entered or changed.

Written by the indexing model from the issue text.