Open Screen

Ensure a bot exists for this meeting, then let the caller poll the ticket. If a live session is already holding, say so; otherwise spawn a TRANSCRIBE-ONLY bot (agent_id=None) — the operator is opening the screen to join by hand, no agent needed — and report it is starting. The modal then polls /screen/ticket until the bot reaches its pre-join hold.

This is what makes the header Open button self-healing: a meeting whose bot ended (alone-timeout, reaper, a finished call) no longer dead-ends on "no live bot" — Open just starts a fresh one.