fix: sync refactor — fix 6 bugs + cache refresh na sync

- setDeletedAt update nu ook updatedAt (bug 2)
- getAllMeasurements filtert deletedAt IS NULL, nieuwe getAllMeasurementsForSync voor sync
- mergeMeasurements detecteert server deleted:true → deletedAt (bug 1)
- syncAll: pull-push split met remoteUpdatedMap, geen double-push (bug 3)
- hard delete alleen na API-succes (bug 4)
- DashboardScreen: refreshCache() na syncAll zodat UI niet op Laden blijft hangen
- deleteMeasurement() dead code verwijderd (bug 5)
- tests: 3 nieuwe testcases voor deleted → deletedAt mapping, 15/15 pass

tests/syncService.test.ts

@@ -53,4 +53,24 @@ describe('mergeMeasurements', () => {
     const r = mergeMeasurements([local], [remote])
     expect(r[0].deletedAt).toBeUndefined()
   })
+
+  it('server deleted flag mapped to deletedAt when remote wins', () => {
+    const local = make({ updatedAt: '2024-06-01T08:00:00.000Z' })
+    const remote: any = { ...make({ updatedAt: '2024-06-03T08:00:00.000Z' }), deleted: true }
+    const r = mergeMeasurements([local], [remote])
+    expect(r[0].deletedAt).toBe('2024-06-03T08:00:00.000Z')
+  })
+
+  it('server deleted flag ignored when local wins', () => {
+    const local = make({ updatedAt: '2024-06-05T08:00:00.000Z' })
+    const remote: any = { ...make({ updatedAt: '2024-06-03T08:00:00.000Z' }), deleted: true }
+    const r = mergeMeasurements([local], [remote])
+    expect(r[0].deletedAt).toBeUndefined()
+  })
+
+  it('server deleted flag works with no local record', () => {
+    const remote: any = { ...make({ id: 'r1', updatedAt: '2024-06-03T08:00:00.000Z' }), deleted: true }
+    const r = mergeMeasurements([], [remote])
+    expect(r[0].deletedAt).toBe('2024-06-03T08:00:00.000Z')
+  })
 })