ReservedComponentException

A section brought its own definition under a name the panel registers itself — a dashboard primitive, or one of the shell's own components (`admin-sidebar`, `admin-section-header`). The registry overwrites silently, so letting it through would repaint every section that names that component — and, for the header, replace the attribution line on every page with the guest's markup. The message names the section, the name it tried to take, and the names that are the panel's.