Restore Studio playflow CTAs after IDE rebuild (B/E/F/G) #2435

Goal

CoS clean-gate remaining kills after #1692 (A) and the Studio IDE rebuild (#2330). Helpers for transcript stages, skip/unknown stack checks, player overlay, and export toast are on main, but the IDE rebuild dropped the playflow CTAs.

Target: https://uvai.io/studio?video=https://www.youtube.com/watch?v=pBsT6v-ciO8

Remaining kills

• B Visible Retry transcript (stages + ETA already in the toolbar status line).
• E review_action cards in Intent with a clear Act on this run CTA.
• F CRITICAL Anonymous path: SeaDance/Cluely stack checks must show skip/unknown and must not block Ship this / Export / Build live. No G.A.T.E. Deploy restore.
• G Soften public reviewed/durable overclaim copy; keep export toast clear of footer overlap.

C (player overlay) and D (export toast) stay as already implemented.

Out of scope

Origin G.A.T.E. Deploy, fake events, ClipToAction, Ship checkout.