Implementation flaw

Hi there,

I think there is an implementation error in the sample project - more specifically, a flaw in the design of CKSyncEngine.
In the SyncedDatabase file, line 350:

self.syncEngine.state.add(pendingRecordZoneChanges: pendingSaves)

This tells the syncEngine what to do when the time is right. Since this piece of information is *not* persisted in this call (I think its persisted in .stateUpdate(let event)), there is a chance that this information is lost if the app crashes between .add(pendingRecordZoneChanges: pendingSaves) and .stateUpdate(let event).

I know this is just a sample project, but I really think this is a flaw in the API design of CKSyncEngine since I do not see an easy way to guarantee correct behavior. A simple fix would be to make .add(pendingRecordZoneChanges: pendingSaves) (and similar methods) async and only complete after .stateUpdate(let event) was called.

What do you think?

Beginne in SyncedDatabase bei Zeile 350 und überprüfe, wie pendingRecordZoneChanges und das stateUpdate-Ereignis behandelt werden. Bewerte das im Issue beschriebene Crash-Fenster und die vorgeschlagene asynchrone API-Änderung; abgeschlossen ist die Aufgabe erst, wenn eine von einem Maintainer bestätigte Lösung für das Datenverlust- oder API-Design-Problem vorliegt.

Vom Indexierungsmodell aus dem Issue-Text verfasst.