The Displays section is hardcoded in AppLayout (not plugin nav). TV Slideshow
(/tv, slides) had no gate at all and Parts Kiosk (/parts-kiosk, printedparts)
was gated on isPluginEnabled - which a registry copied from a full site reports
true even when the plugin was never staged, so both showed on a lean site and
dead-ended blank. Now each Displays link (Shopfloor, TV Slideshow, Parts Kiosk)
is gated by whether its route is registered in this build (router.getRoutes),
and the Displays header hides when none are present. Route existence is the true
'is it in this build' test.
a5ba973974