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/api/src/broker/expand.ts

@@ -45,6 +45,13 @@ export interface CalendarOccurrence {
    * Client routes Schedule-X calendarId as String(ownerUserId) for personal calendars.
    */
   ownerUserId: number
+  /**
+   * Display name of the calendar owner (users.displayName).
+   * Null when the user has not set a display name.
+   * The popover uses this to show the owner name for personal events;
+   * falls back to calendarName when null.
+   */
+  ownerName: string | null
   /** Hex color: users.color for personal calendars, '#F25C7A' for shared-family */
   color: string
   /** True when this occurrence belongs to the shared-family calendar (calendars.isShared=true) */
@@ -67,6 +74,8 @@ export interface OccurrenceMeta {
   calendarId: number
   calendarName: string
   ownerUserId: number
+  /** Display name of the calendar owner; null when users.displayName is not set */
+  ownerName: string | null
   /** Hex color: pre-computed by the route (users.color or shared-family constant) */
   color: string
   isShared: boolean
@@ -162,6 +171,7 @@ export function expandOccurrences(
   calendarId: number,
   calendarName: string,
   ownerUserId: number,
+  ownerName: string | null,
   color: string,
   isShared: boolean,
 ): CalendarOccurrence[] {
@@ -229,6 +239,7 @@ export function expandOccurrences(
         calendarId,
         calendarName,
         ownerUserId,
+        ownerName,
         color,
         isShared,
         title: event.summary ?? '',
@@ -274,6 +285,7 @@ export function expandOccurrences(
       calendarId,
       calendarName,
       ownerUserId,
+      ownerName,
       color,
       isShared,
       title: event.summary ?? '',

apps/api/src/routes/events.ts

@@ -82,6 +82,7 @@ eventsRouter.get('/', zValidator('query', eventsQuerySchema), async (c) => {
         isShared: calendars.isShared,
         userId: users.id,
         userColor: users.color,
+        ownerName: users.displayName,
       })
       .from(calendarEvents)
       .innerJoin(calendars, eq(calendarEvents.calendarId, calendars.id))
@@ -126,6 +127,7 @@ eventsRouter.get('/', zValidator('query', eventsQuerySchema), async (c) => {
         row.calendarId,
         row.calendarName ?? '',
         row.userId,
+        row.ownerName ?? null,
         color,
         row.isShared,
       )