- Replace hardcoded Bearer token default with empty string
- Remove auto-save in useEffect that wrote defaults to SecureStore
without user consent on first app launch
Fixes#2
- 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