Add a visual indicator for pinned tabs in vertical tab layout when the sidebar is at minimum width

In the screenshot below, several of the tabs at the top are pinned, but there's no indication. This is only an issue when the sidebar is at its narrowest width.

The lack of an idicator makes some behavior hard to predict. For example, when you don't know if a tabbed is pinned, you can't predict what command-w will do

It could be good to add a divider/horizontal rule when the sidebar is fully narrowed

Or, add a "thumbtack"/pinned icon to the lower left of the favicon when the sidebar is fully narrowed

Or, have the total number of pinned and unpinned tabs above each respective "tab area", similar to how it is when the sidebar is more expanded. Perhaps the number would be the size of its own favicon, in this case.