* Correctly handle the re-opening of the main window.
Add an additional safe-guard to ensure only one main window exists.
Make sure all secondary windows use the correct tint colour.
* Fix a bug where the settings screen isn't shown on macOS when the AppLock feature is enabled.
- stop using multiple background task, the appCoordinator sync one is enough for the whole app
- move the AppMeditor to the MainActor
- expose the WindowManager through the AppMediator
- hide sensitive WindowManager API behind a different protocol
- remove the now unnecessary `BackgroundTaskService`