fix(02): show owner name / Family in event popover footer

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.

apps/pwa/src/components/EventDetailPopover.tsx

@@ -369,8 +369,12 @@ export function EventDetailPopover(props: ScheduleXEventModalProps = {}) {
             }}
             aria-hidden="true"
           />
-          {/* Plain text — XSS guard */}
-          {occurrence.calendarName}
+          {/* Plain text — XSS guard (T-02e-01).
+              Show 'Family' for shared-calendar events; owner display name for personal
+              events; fall back to calendarName when ownerName is null. */}
+          {occurrence.isShared
+            ? 'Family'
+            : (occurrence.ownerName ?? occurrence.calendarName)}
         </div>
 
         {/* Phase 3 footer action area — Phase 3 adds edit/delete actions here (D-08) */}