New insightsEntry field ('show' | 'hide', default 'show') in the
dsh-context settings namespace, edited from the Plugin configuration
card. The sidebar entry subscribes to the store and renders null while
hidden; the seat stays registered so flipping back needs no remount.
Fails open everywhere: a schema-less host, an unserved namespace, a
section without the field, a stale persisted value (loose union), or a
write that never persists all resolve to the visible entry.