Right-click now fetches the item's com.canonical.dbusmenu layout and renders it
in a GTK popover anchored to the icon, instead of calling the SNI ContextMenu
method. Fixes menus opening at screen (0,0) for apps that implement it (Discord)
and gives a menu at all for dbusmenu-only apps (nm-applet, blueman). Supports
sections, submenus, checkmarks, icons and Event-on-activate; themed to match the
suite (.station-tray-menu).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>