you could build a report and have it set to refresh, then dock that in a corner of your desktop
other than that, don't know of anything
The "dirty" state of a worksheet is shown for the editor for content only (italic title=not saved; normal tile=saved to file). However, the DB state is ignored, as you pointed out. It would affect all windows with the associated connection.
What you want already exists for other database-associated editors. E.g. when you change a row of a table. The non-committed state is indicated on the row that has been changed (with a star) and on the title of the tab (italic text). So this concept is partially implemented in SQL Developer. I guess it's possible to implement that as a new feature for worksheets as well. Either in SQL Developer or as a custom extension.