GeschichteSidebar gains optional geschichteId/items props and renders the
panel only when geschichteId is set. GeschichteEditor derives both from
its existing GeschichteView prop — null on /geschichten/new, so the panel
stays hidden there (create-then-edit, same as journeys). JourneyEditor's
sidebar call site is untouched, so journeys never show the panel.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>