A SwiftUI app where background DB cleanup caused issues weeks later, what happened there?

A SwiftUI app experienced intermittent UI freezes caused by a background database compaction task sharing the same store file with the main thread. The root cause was lack of isolation: the background job ran while the app could still reopen the same store, occasionally causing brief locks that manifested as random scroll freezes. The fix was strict isolation, giving the background job its own store file to prevent shared state contention.