- Full backend pytest currently has pre-existing failures unrelated to this task scope (5 failing tests in routines/skincare helpers after schema changes in this branch context).
- Existing historical migration  executes , which breaks full SQLite-from-base upgrades; T2 QA used a synthetic DB pinned at revision  to validate the new migration behavior in isolation.
- Correction: historical migration 7c91e4b2af38 runs DROP TYPE IF EXISTS pricetier, which breaks SQLite full-chain upgrades; T2 evidence therefore uses a synthetic DB pinned to revision 9f3a2c1b4d5e for isolated migration validation.