v0.2.1 — auto-update + policy-in-the-loop

Studio now updates itself: it checks the signed manifest on the newest release shortly after launch and offers an update ⟳ chip — install once, stay current. Also in this release: the policy-in-the-loop bridge (a trained checkpoint from your python env drives the live sim via caliper-learn drive; record its rollouts as episodes) and the post-release adversarial review fix wave (9 verified findings, 9 fixed with regression tests). The dmg is signed & notarized (Business Lion LLC) — 11 MB with the MuJoCo contact sim inside, no Gatekeeper warning. Full notes: CHANGELOG.