Backend:
- expand.ts: add ownerName: string | null to CalendarOccurrence
interface and expandOccurrences() signature; thread it onto every
emitted occurrence.
- events.ts: SELECT users.displayName as ownerName in the join; pass
it to expandOccurrences().
Frontend:
- client.ts: add ownerName: string | null to CalendarOccurrence.
- EventDetailPopover.tsx: render isShared ? 'Family' :
(ownerName ?? calendarName) in the footer instead of calendarName.
Tests:
- expand.test.ts: pass ownerName to all expandOccurrences() calls;
assert ownerName is carried onto occurrences in the DST test.
- events.test.ts: add ownerName to mock rows; assert ownerName present
on occurrences; add ownerName assertion to timed-recurring test.
- EventDetailPopover.test.tsx: add ownerName to fixtures; split
"calendar name in footer" into three targeted tests covering
personal-with-owner, shared→Family, and null-owner fallback.