# Track closed at decision playbook (issue #5)

Learner finished lesson 4 (decision playbook) and can run the four gates — job, shape, lifetime/isolation, ship risks — to defend or reject `sessionStorage` in a design review. Mission success criteria from issue #5 are met at lesson-first depth (external primaries optional). Keep `reference/decision-playbook.html` + `integration-checklist.html` + `storage-api.html` for real reviews. No further lessons planned unless a new gap appears (e.g. deep opener/private-mode lab).