useUserPlan had its own module-level cache + fetch-once-on-mount, separate
from useMe's invalidateMe(). So the __DEV__ tier-override toggle (which calls
invalidateMe()) never reached useUserPlan consumers → the app didn't react to
a plan switch. Now useUserPlan just reads me.plan from useMe → inherits its
live-invalidation, the toggle propagates everywhere.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>