Registration-edit errors were set into a page-level error state rendered
behind the edit modal overlay; they now render inside the modal. The
"Show past events" toggle only hid date-based past events, letting
cashup-closed events leak through by default; a shared isEventOver()
check now covers both, applied to registrations, tickets, and the
Edit button visibility (mirroring the backend's own edit block).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
joshua