Pre-event setup wizard

[if-else-repeat]

Currently zones and operators must be added via API calls.
Build a guided web UI that walks an organizer through:

1. Create event (name, date, venue, capacity)
2. Add zones (name, label, capacity)
3. Add operators (bulk import via CSV or manual)
4. Generate printable briefing cards

This is the biggest adoption barrier for non-technical organizers.