Clearing app data loses local tasks and resurrects archived cloud tasks

Problem

Clearing application data permanently loses all local tasks, including archived ones, with no way to recover them. Separately, after reinstalling and clearing data again, cloud tasks that were stopped and archived weeks or months ago reappear instead of staying stopped and archived. Reported by Richard.

Expected behavior

• Local tasks, including archived ones, should survive or be recoverable rather than being silently destroyed when application data is cleared.
• Cloud tasks that were previously stopped and archived should keep that state after a data clear or reinstall, not resync as active and unarchived.

Steps to reproduce

1. Clear application data (originally done to work around other buggy behavior).
2. Observe that all local tasks, including archived ones, are gone.
3. Delete and reinstall the app, then clear application data again.
4. Observe that cloud tasks that were stopped and archived weeks or months ago reappear.

Possibly related: PostHog/posthog#76218 (archived tasks leaking across accounts after account switch).

No file, test, or entry point is named. Start by reproducing the clear-data and reinstall sequence, then locate the local task persistence and cloud resync paths; done means local tasks are recoverable and stopped, archived cloud tasks remain stopped and archived after both operations.