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/tests/routes/events.test.ts

@@ -70,19 +70,22 @@ describe('GET /api/events', () => {
     expect(res.status).toBe(400)
   })
 
-  it('returns occurrences with color and isShared fields for valid window', async () => {
+  it('returns occurrences with color, isShared, and ownerName fields for valid window', async () => {
     const { app } = await import('../../src/index.js')
     const res = await app.request('/api/events?start=2026-06-01&end=2026-07-01')
     expect(res.status).toBe(200)
-    const body = await res.json() as { occurrences: Array<{ color: string; isShared: boolean }> }
+    const body = await res.json() as { occurrences: Array<{ color: string; isShared: boolean; ownerName: string | null }> }
     expect(body).toHaveProperty('occurrences')
     expect(Array.isArray(body.occurrences)).toBe(true)
-    // Each occurrence must carry color + isShared (may be empty array if DB is mocked empty)
+    // Each occurrence must carry color + isShared + ownerName (may be empty array if DB is mocked empty)
     for (const occ of body.occurrences) {
       expect(occ).toHaveProperty('color')
       expect(typeof occ.color).toBe('string')
       expect(occ).toHaveProperty('isShared')
       expect(typeof occ.isShared).toBe('boolean')
+      expect(occ).toHaveProperty('ownerName')
+      // ownerName is string | null — both are valid
+      expect(occ.ownerName === null || typeof occ.ownerName === 'string').toBe(true)
     }
   })
 
@@ -100,6 +103,7 @@ describe('GET /api/events', () => {
         isShared: false,
         userId: 1,
         userColor: '#4A90D9',
+        ownerName: 'Alice',
       },
     ]
 
@@ -107,7 +111,7 @@ describe('GET /api/events', () => {
     const res = await app.request('/api/events?start=2026-06-01&end=2026-07-01')
     expect(res.status).toBe(200)
 
-    const body = await res.json() as { occurrences: Array<{ uid: string; start: string; allDay: boolean }> }
+    const body = await res.json() as { occurrences: Array<{ uid: string; start: string; allDay: boolean; ownerName: string | null }> }
     expect(body.occurrences.length).toBeGreaterThan(0)
 
     // All returned occurrences must be inside [2026-06-01, 2026-07-01)
@@ -118,6 +122,8 @@ describe('GET /api/events', () => {
       const startDate = occ.start.slice(0, 10) // 'YYYY-MM-DD'
       expect(startDate >= '2026-06-01').toBe(true)
       expect(startDate < '2026-07-01').toBe(true)
+      // ownerName from the mock row must be threaded through
+      expect(occ.ownerName).toBe('Alice')
     }
   })
 
@@ -135,6 +141,7 @@ describe('GET /api/events', () => {
         isShared: false,
         userId: 1,
         userColor: '#50C878',
+        ownerName: 'Bob',
       },
     ]