I vibecoded this functionality into the original breadcrumbs extension: joelchan/roam-breadcrumbs-extension#1 and would like to add the functionality to this codebase too.
It worked like this:

My own attempts to apply those changes to this codebase resulted in a bug where shift-clicking just selected text in the main/sidebar windows and/or this new breadcrumbs sidebar, rather than opening the page in the right sidebar