Stalwart 1.0 refuses series properties such as privacy and the
organizer on a single occurrence unless they repeat the series' value,
and refuses them inside a recurrence override on the base event. The
event modal sent privacy "public" on every save, so editing one
occurrence of a series without CLASS failed, and so did every change to
an occurrence the browser expanded.
- leave series and per-event keys out of changes to one occurrence
- write base-event overrides as before and, if the server refuses
series keys there, repeat the write once without them and remember
that
- stop resetting status, free/busy and privacy when an event is edited