# Lesson 5 complete; external sources still unread

Learner finished lesson 0005 (deal-breakers & integration risks) without additional external reads. Treat as known from lessons: wrong-tool redirects (Cache / OPFS / memory / server); best-effort storage under quota and eviction; schema/version as deploy; multi-tab upgrade and multi-writer product conflicts; mid-tx await red flag; sync policy is product not API. External MDN/web.dev depth still deferred. Next ZPD: synthesis decision playbook (mission payoff).