Admin event create form:
- Wraps body in a form-layout/form-main container for upcoming sidebar work.
- Bigger autoresize textareas for description/content; adds an Agenda
textarea (one item per line, persisted as event.agenda).
- Reorganises settings into Event Settings + conditional Cancellation
Message sections.
- Pulls event-type options from EVENT_TYPES; location becomes optional;
passes displayTimezone through to NaturalDateInput.
NaturalDateInput: rewritten to a single always-visible UInput with chrono
parsing and trailing status icon, instead of toggling between input and
parsed-summary blocks. Cleaner state model (rawInput / parsedDate /
isValid / hasError) and timezone-aware update emission.
Jennie Robinson Faber
4a05e91715