prevent workspace switching to empty workspace when tabs are removed

When all tabs in the current workspace are removed, the extension would incorrectly switch to an empty workspace, leaving the user with no visible tabs. This change ensures a fallback workspace with tabs is selected, or a new tab is created in the current workspace to maintain a usable interface.

icon fix

Add browser action to open options page when toolbar icon is clicked.

The issue of tabs not being remembered in spaces after closing the browser or extension has been resolved.