pfSense

I wondered about that also, at the time of the bootstrap conversion, but there was enough going on that I never followed it up.
Here is a bit of demo code to start discussion:
https://github.com/pfsense/pfsense/pull/3364

Proposed solution is out for review/test https://github.com/pfsense/pfsense/pull/3369

Phil: That looks great, thanks! I guess the same can be used for packages (the PHP files I mean, not XML), right?

Yes, for packages with XML the pkg.php and pkg_edit.php try to put some reasonable breadcrumb links in (try the Notes package, which has XML that generates a base form (controlled by pkg.php) and has Edit Note (controlled by pkg_edit.php). The existing way pkg_edit.php generates the breadcrumb list is a bit odd - e.g. when editing a note the breadcrumb list is "Status:Notes / Edit / Notes" - the "Edit" ends up in the middle, and I gave that the "@self" link, and the others take you back to the main Notes page. The order of that breadcrumb list could be fixed better - but that was an existing "feature" that was out-of-scope for me to start messing with.

Packages that just have a simple "2-node" breadcrumb list ("Services / Cron") will get a self-reference link on that last entry (which effectively refreshes the page), and so need no changes.

Packages with >2-node breadcrumb lists in their PHP files will get a self-reference on the last element of each list. To make other links in the list, they need to be modified to define $pglinks appropriately.

Works.