playground

Document lessons learned after each Sprints smoke test in playground, especially observed failures, manual recoveries, product gaps, and follow-up hardening work, by writing a concise Markdown note under docs/lessons_learned.

Run a fresh Sprints smoke test for playground by syncing main, reinstalling the Sprints plugin, selecting the workflow root, applying the active workflow contract, starting managed daemons, creating or selecting a smoke issue, and observing until completion or operator attention.

Clean the playground repository before a fresh Sprints smoke test by stopping active Sprints daemons, closing open playground PRs, and removing active workflow labels from open issues.