on_mount hook that records, for the admin chrome in MishkaCmsCore.Layouts: the current request path as @current_path (so the sidebar highlights the active item — updates on live navigation too), @notification_count (failed/retrying runtime jobs, shown as the topbar bell badge), and @current_user with its :permissions loaded. Attached to every admin page via MishkaCmsCore.ExtensionLiveView.

It also puts the page in the language its admin reads the dashboard in — MishkaCmsCore.Runtime.Languages.admin/1, chosen in the topbar's user menu — as Gettext's locale and as @admin_language, with the choices the menu offers as @admin_languages. The menu's Sign out is the site's sign-out page in the language its admin reads the site in, @sign_out_path (MishkaCmsCore.Runtime.Plugs.SiteLookupPlug.auth_address/3). And it names the page's @footer_credit: the name and address of the extension that owns the page, or nil on the core's own (MishkaCmsCore.Sidebar.credit/1).

The sidebar follows its settings live: the hook subscribes to MishkaCmsCore.Sidebar.changed/1 for the menu its viewer is shown and raises @sidebar_version, which MishkaCmsCore.Layouts.sidebar/1 redraws on. Changes that arrive together are drawn once. Each redraw emits [:mishka_cms, :sidebar, :redrawn] from the page's own process as it raises @sidebar_version, with the new version as its measurement and the page's view as its metadata, so whatever asks the page after that event is answered with the redrawn sidebar.

Loading the permissions here rather than where they are used matters: MishkaCmsCore.Sidebar asks whether the viewer may see each nav entry, once per entry, through AccessPermissions.match?/3, which loads an unloaded actor — so without this the chrome would issue a query on every render.