Design for moving off the deprecated androidx.security:security-crypto to
Tink Android-Keystore-backed storage, without ever losing the couple key.
Covers: the load-bearing hazard (SecurePreferencesFactory.reset() silently
WIPES the couple key on any read failure) which must be removed first;
lazy dual-read + re-wrap + verify-then-clean migration; fail-closed (recover,
never delete) failure matrix; consumer ordering (couple key last); staged RC
rollout + content-free telemetry; test plan; open questions for the owner.
No implementation ships until the owner approves this design (Batch 5.1 gate).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>