Simplify preferences model by doing a bulk load/save together with
load/save Profile. ModulePreferences is now a struct rather than an
ObservableObject, because it doesn't need ad hoc observation. It's just
a binding to ProfileEditor.preferences
Fix:
- Disable CloudKit in tunnel singleton of PreferencesManager
(.sharedForTunnel)
Additionally:
- Replace MainActor in PreferencesManager with Sendable (immutable)
- Replace MainActor from ProviderPreferencesRepository with Sendable
(syncs on NSManagedObjectContext)
- Drop ModuleMetadata for good
